[{"modality": "Radiography", "region": "head", "region_label": "Head / Skull", "exam": "Skull series (AP axial Towne, lateral, PA axial Caldwell, PA)", "image": {"file": "radiography__head__skull-series.jpg", "caption": "AP axial (Towne) skull radiograph.", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Foramina_parietalia_in_Schaedelaufnahme_nach_Town_-_53jw.jpg"}, "questions": [{"q": "For a lateral skull projection, which line is placed perpendicular to the image receptor?", "options": ["Orbitomeatal line", "Midsagittal plane", "Infraorbitomeatal line", "Interpupillary line"], "answer_index": 3, "explanation": "The interpupillary line is perpendicular and the midsagittal plane parallel to the IR, which prevents tilt and rotation."}, {"q": "For a PA skull with the OML perpendicular to the IR and a perpendicular central ray, the petrous ridges should appear:", "options": ["In the lower third of the orbits", "Below the inferior orbital rims", "Superimposed on the supraorbital margins, filling the orbits", "Through the foramen magnum"], "answer_index": 2, "explanation": "With no CR angle the petrous ridges fill the orbits; a 15-degree caudal angle (Caldwell) moves them to the lower third of the orbits."}, {"q": "Which part of the skull is best demonstrated on an AP axial (Towne) image like this one?", "options": ["Occipital bone", "Frontal bone", "Facial bones", "Nasal bones"], "answer_index": 0, "explanation": "The caudal angle projects the occipital bone, foramen magnum and petrous pyramids free of the facial bones."}]}, {"modality": "Radiography", "region": "head", "region_label": "Head / Skull", "exam": "Facial bones (Waters, Caldwell, lateral)", "image": {"file": "radiography__head__facial-bones.jpg", "caption": "Parietoacanthial (Waters/occipitomental) projection of the facial bones.", "credit": "Ptrump16", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Paranasal_sinuses_radiograph_occipitomental_projection.jpg"}, "questions": [{"q": "On a correctly positioned parietoacanthial (Waters) projection like this one, the petrous ridges should project:", "options": ["Within the lower third of the orbits", "At the level of the supraorbital margins", "Through the foramen magnum", "Just below the maxillary sinuses"], "answer_index": 3, "explanation": "Extending the chin so the MML is perpendicular places the petrous ridges just inferior to the maxillary sinuses, clearing the maxillae and orbital floors."}, {"q": "For the Waters method, the orbitomeatal line forms what angle with the image receptor?", "options": ["15 degrees", "37 degrees", "25 degrees", "53 degrees"], "answer_index": 1, "explanation": "The OML is at 37 degrees to the IR and the mentomeatal line is perpendicular, with a horizontal CR exiting at the acanthion."}, {"q": "On a Waters image, the petrous ridges overlap the lower maxillary sinuses. How should the position be corrected?", "options": ["Flex the chin toward the chest", "Extend the chin more", "Rotate the head 15 degrees", "Add a caudal CR angle"], "answer_index": 1, "explanation": "Petrous ridges over the maxillary sinuses mean the neck was not extended enough; raising the chin moves them below the sinuses."}]}, {"modality": "Radiography", "region": "head", "region_label": "Head / Skull", "exam": "Paranasal sinuses (erect, horizontal beam)", "image": {"file": "radiography__head__paranasal-sinuses.jpg", "caption": "PA (occipitofrontal) sinus radiograph.", "credit": "Ptrump16", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Paranasal_sinuses_radiograph_occipitofrontal.jpg"}, "questions": [{"q": "Why must paranasal sinus projections be performed erect with a horizontal beam?", "options": ["To reduce patient dose", "To show air-fluid levels", "To magnify the sinuses", "To remove the petrous ridges"], "answer_index": 1, "explanation": "Fluid layers only with a horizontal beam and an upright patient, so air-fluid levels can be seen."}, {"q": "A PA (Caldwell-type) sinus projection like this one best demonstrates which sinuses?", "options": ["Maxillary sinuses", "Sphenoid sinuses", "Mastoid air cells", "Frontal and anterior ethmoid sinuses"], "answer_index": 3, "explanation": "The Caldwell shows the frontal sinuses above the orbits and the anterior ethmoid air cells between them; the maxillary sinuses are best on the Waters."}, {"q": "The submentovertex (SMV) projection of the sinuses best demonstrates the:", "options": ["Sphenoid and ethmoid sinuses", "Frontal sinuses", "Mastoid air cells only", "Maxillary sinus floors"], "answer_index": 0, "explanation": "In the SMV the sphenoid sinuses are seen anterior to the foramen magnum, with the ethmoids anterior to them."}]}, {"modality": "Radiography", "region": "head", "region_label": "Head / Skull", "exam": "Mandible and TMJs", "image": {"file": "radiography__head__mandible-and-tmjs.jpg", "caption": "Frontal (Clementschitsch-type PA) mandible radiograph with a condylar process fracture.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Fraktur_Gelenkfortsatz_Mandibula_mit_Abkippung_nach_innen_4W_-_CR_Clementschitsch_-_001.jpg"}, "questions": [{"q": "For the PA axial projection of the mandible to show the rami and condyles, the central ray is angled:", "options": ["20-25 degrees caudad", "37 degrees caudad", "20-25 degrees cephalad", "Perpendicular to the IR"], "answer_index": 2, "explanation": "A 20-25 degree cephalad angle, exiting at the acanthion, elongates the condylar processes and projects them below the mastoids."}, {"q": "Why are TMJ studies usually performed with both open-mouth and closed-mouth images?", "options": ["To lower patient dose", "To show only the coronoid processes", "To show condylar movement relative to the articular eminence", "To magnify the joint space"], "answer_index": 2, "explanation": "Comparing open and closed positions shows how far the condyle glides forward, which is the functional information the study is for."}, {"q": "This frontal mandible image shows a fracture of the condylar process. Which projection is also commonly used to demonstrate both condylar necks?", "options": ["AP axial (modified Towne) mandible", "Lateral nasal bones", "PA axial Caldwell", "Lateral skull"], "answer_index": 0, "explanation": "An AP axial projection with about 35-40 degrees caudal angle shows the condyles and TMJ region bilaterally for comparison."}]}, {"modality": "Radiography", "region": "head", "region_label": "Head / Skull", "exam": "Nasal bones", "image": {"file": "radiography__head__nasal-bones.jpg", "caption": "Lateral nasal bones radiograph showing a nasal bone fracture.", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Medical_X-Ray_imaging_NJR06_Nevit_nasal_bone_fracture.jpg"}, "questions": [{"q": "The superoinferior (axial) tangential projection of the nasal bones is used to show:", "options": ["The frontal sinus", "The sella turcica", "The mandibular condyles", "Medial or lateral displacement of nasal bone fragments"], "answer_index": 3, "explanation": "Seen from above, the nasal bones and septum are shown tangentially, so sideways displacement that a lateral cannot show is visible."}, {"q": "Why are both right and left lateral nasal bone images routinely obtained?", "options": ["To demonstrate the frontal sinus", "Each lateral best shows the side closest to the IR, so both are taken for comparison", "To reduce motion blur", "To show the sphenoid sinus"], "answer_index": 1, "explanation": "The side nearer the IR has less magnification and blur, so imaging both sides allows each nasal bone to be evaluated."}, {"q": "Compared with a lateral skull, the lateral nasal bones projection is best performed with:", "options": ["A grid and high kVp", "A small focal spot and lower exposure factors", "A 72-inch SID", "A large focal spot to shorten exposure"], "answer_index": 1, "explanation": "The nasal bones are thin and small, so detail technique (small focal spot, low mAs and kVp, no grid) shows fine fracture lines like those on this image."}]}, {"modality": "Radiography", "region": "head", "region_label": "Head / Skull", "exam": "Orbits", "image": {"file": "radiography__head__orbits.jpg", "caption": "Waters view with a right zygomaticomaxillary (tripod) fracture involving the orbital walls.", "credit": "I enjoy sandwiches", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:Tripod_fx_labeled_with_arrows.jpg"}, "questions": [{"q": "For the parieto-orbital oblique (Rhese method), which line is placed perpendicular to the IR?", "options": ["Orbitomeatal line", "Infraorbitomeatal line", "Interpupillary line", "Acanthiomeatal line"], "answer_index": 3, "explanation": "The chin, cheek and nose rest on the IR with the AML perpendicular, which projects the optic canal end-on."}, {"q": "For the Rhese method, the midsagittal plane forms what angle with the image receptor?", "options": ["53 degrees", "37 degrees", "45 degrees", "15 degrees"], "answer_index": 0, "explanation": "The head is rotated so the MSP is 53 degrees to the IR with the acanthiomeatal line perpendicular; both sides are imaged for comparison."}, {"q": "This Waters image shows a zygomaticomaxillary (tripod) fracture. Which areas does a tripod fracture classically involve?", "options": ["Nasal bones, frontal sinus and mandible", "Sella turcica, clivus and dens", "Zygomatic arch, lateral orbital wall and inferior orbital rim/maxilla", "Both mandibular condyles and the symphysis"], "answer_index": 2, "explanation": "The zygoma is broken away at its connections to the temporal, frontal and maxillary bones, which the Waters view shows well."}]}, {"modality": "Radiography", "region": "chest", "region_label": "Chest / Thorax", "exam": "PA and lateral chest", "image": {"file": "radiography__chest__pa-and-lateral-chest.jpg", "caption": "Normal lateral chest radiograph.", "credit": "Mikael Häggström", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:Normal_lateral_chest_radiograph_(X-ray).jpg"}, "questions": [{"q": "Why is the PA chest performed at a 72-inch (180 cm) SID?", "options": ["To minimize magnification of the heart", "To increase patient dose to the lungs", "To increase OID", "To allow use of a smaller focal spot"], "answer_index": 0, "explanation": "A long SID reduces magnification and distortion of the heart and mediastinum."}, {"q": "Why is the PA chest exposure usually made on the second full inspiration?", "options": ["It reduces heart size", "It raises the diaphragm", "Patients can usually inhale more deeply on the second breath", "It shows pleural fluid better"], "answer_index": 2, "explanation": "A second deep breath usually gives fuller lung expansion without strain, lowering the diaphragm for better lung coverage."}, {"q": "On a lateral chest such as this one, which finding shows the patient was NOT rotated?", "options": ["Posterior ribs are nearly superimposed", "The sternum is seen en face", "The clavicles are level", "Ten posterior ribs are above the diaphragm"], "answer_index": 0, "explanation": "With a true lateral, the posterior ribs superimpose (allowing slight separation from divergence); obvious double rib contours indicate rotation."}]}, {"modality": "Radiography", "region": "chest", "region_label": "Chest / Thorax", "exam": "AP supine or semi-erect chest (portable)", "image": {"file": "radiography__chest__ap-supine-or-semi-erect-chest.jpg", "caption": "Bedside supine AP chest with a layering pleural effusion.", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:14-01-Erguss_im_Liegen.png"}, "questions": [{"q": "On a supine AP chest such as this bedside image, a pleural effusion typically appears as:", "options": ["A meniscus at the costophrenic angle", "An air-fluid level", "A sharp horizontal line at the base", "A diffuse haziness over the hemithorax as fluid layers posteriorly"], "answer_index": 3, "explanation": "Lying down, fluid spreads along the posterior chest, so it raises the density of the whole hemithorax instead of forming a meniscus."}, {"q": "For a semi-erect portable AP chest, the central ray should be:", "options": ["Angled 15 degrees cephalad", "Angled caudad so it is perpendicular to the long axis of the sternum", "Horizontal regardless of patient position", "Angled 45 degrees medially"], "answer_index": 1, "explanation": "A caudal angle perpendicular to the sternum keeps the clavicles from projecting over the apices and reduces lordotic distortion."}, {"q": "Why should a portable chest image be labeled with the patient position (supine or semi-erect, with angle)?", "options": ["To meet billing rules only", "So heart size and fluid or air findings are interpreted correctly", "To reduce patient dose", "So the image can be processed faster"], "answer_index": 1, "explanation": "Position changes heart size and whether air-fluid levels can be seen, so the reader must know how the image was taken."}]}, {"modality": "Radiography", "region": "chest", "region_label": "Chest / Thorax", "exam": "Lateral decubitus chest", "image": null, "questions": [{"q": "A patient may have fluid in the right pleural space and cannot stand. Which projection best shows the fluid?", "options": ["Left lateral decubitus", "AP lordotic", "Dorsal decubitus abdomen", "Right lateral decubitus"], "answer_index": 3, "explanation": "For pleural fluid, the affected side goes down, so a right lateral decubitus lets fluid layer along the dependent chest wall."}, {"q": "For a lateral decubitus chest, the patient's arms are:", "options": ["At the sides", "Crossed over the chest", "Behind the back", "Raised above the head so they are clear of the lung fields"], "answer_index": 3, "explanation": "Raising both arms removes their soft tissue from the lungs, much like the arm position for an erect lateral chest."}, {"q": "Why is the patient placed on a radiolucent pad or firm support for a lateral decubitus chest?", "options": ["So the dependent side of the chest is not cut off at the edge of the image", "To reduce exposure time", "To magnify the lung bases", "To keep the arms out of the field"], "answer_index": 0, "explanation": "A soft mattress lets the dependent side sink below the field; raising the patient makes sure the down-side lung, where fluid layers, is included."}]}, {"modality": "Radiography", "region": "chest", "region_label": "Chest / Thorax", "exam": "AP lordotic", "image": {"file": "radiography__chest__ap-lordotic.jpg", "caption": "AP lordotic (apicolordotic) chest view.", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:X1300073_Nevit.jpg"}, "questions": [{"q": "For the AP lordotic chest, the patient stands about a foot from the IR and leans back until the:", "options": ["Hips touch the IR", "Chest is turned 45 degrees", "Shoulders, neck and back of the head rest against the IR", "Abdomen touches the IR"], "answer_index": 2, "explanation": "Leaning back with the shoulders on the IR tilts the upper chest so the clavicles project above the apices."}, {"q": "If a patient is too ill to lean back for a lordotic, the AP axial projection is done with the central ray angled:", "options": ["15-20 degrees caudad", "45 degrees cephalad", "15-20 degrees cephalad", "Perpendicular to the IR"], "answer_index": 2, "explanation": "A cephalad angle of 15-20 degrees projects the clavicles above the apices without the patient leaning back."}, {"q": "On a well-positioned lordotic image like this one, the clavicles appear:", "options": ["Nearly horizontal and above the lung apices", "Crossing the mid-lung fields", "Below the apices", "Steeply angled downward medially"], "answer_index": 0, "explanation": "Correct lordotic positioning shows the clavicles almost horizontal and projected superior to the apices, which are seen free of bone."}]}, {"modality": "Radiography", "region": "chest", "region_label": "Chest / Thorax", "exam": "Ribs above and below the diaphragm", "image": {"file": "radiography__chest__ribs-above-and-below-the-diaphragm.jpg", "caption": "Chest radiograph with old left lateral rib fractures (circled).", "credit": "James Heilman, MD", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Fracturedribsmarked.jpg"}, "questions": [{"q": "For rib projections below the diaphragm, the exposure is taken on:", "options": ["Suspended full inspiration", "Shallow breathing", "A Valsalva maneuver", "Suspended expiration"], "answer_index": 3, "explanation": "Expiration raises the diaphragm so the lower ribs are seen against the abdomen; lower technique ribs are usually done supine."}, {"q": "Before positioning for a rib series, how is the area of injury often localized?", "options": ["By marking the skin with ink only", "By placing a small metallic marker over the site of pain", "By using a wider collimation", "By asking the radiologist to guess"], "answer_index": 1, "explanation": "A small marker over the painful spot shows the radiologist exactly where to look for a fracture."}, {"q": "This image shows healed fractures of the left lateral ribs. In a trauma rib series, why is a PA chest commonly added?", "options": ["To lower total dose", "To check for pneumothorax, hemothorax or lung contusion", "To show the sternum", "To replace the oblique views"], "answer_index": 1, "explanation": "Rib fractures can tear the pleura or lung, so an erect PA chest is used to detect complications that matter more than the fracture itself."}]}, {"modality": "Radiography", "region": "chest", "region_label": "Chest / Thorax", "exam": "Sternum (RAO, lateral)", "image": {"file": "radiography__chest__sternum.jpg", "caption": "Lateral sternum showing a displaced sternal fracture (arrow).", "credit": "James Heilman, MD", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:DisplacedSternalFracture.jpg"}, "questions": [{"q": "Which breathing technique is often used for the RAO sternum?", "options": ["Suspended full inspiration", "Suspended expiration", "A Valsalva maneuver", "Slow, shallow breathing during a longer exposure"], "answer_index": 3, "explanation": "Breathing during a long, low-mA exposure blurs the overlying lung markings and ribs while the sternum stays sharp."}, {"q": "Compared with an average patient, a patient with a large, deep chest needs how much rotation for the RAO sternum?", "options": ["Less rotation", "More rotation", "The same rotation", "No rotation, a PA instead"], "answer_index": 0, "explanation": "A deep chest already moves the sternum far from the spine, so less rotation clears it; a thin chest needs more."}, {"q": "For a lateral sternum like this one, the patient's shoulders and arms should be:", "options": ["Raised above the head", "Rolled forward", "Drawn back so the humeral heads do not overlap the sternum", "Placed at the patient's sides with palms forward"], "answer_index": 2, "explanation": "Pulling the shoulders back clears soft tissue and humeri from the sternum, which is seen in profile on the lateral."}]}, {"modality": "Radiography", "region": "chest", "region_label": "Chest / Thorax", "exam": "Soft tissue neck", "image": {"file": "radiography__chest__soft-tissue-neck.jpg", "caption": "Lateral soft tissue neck with prevertebral swelling from a retropharyngeal abscess (arrow).", "credit": "James Heilman, MD", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Retroabscess10.JPG"}, "questions": [{"q": "Compared with a lateral cervical spine, the lateral soft tissue neck uses:", "options": ["Higher kVp to penetrate bone", "A grid and much higher mAs", "Lower exposure factors to show air and soft-tissue interfaces", "A double exposure"], "answer_index": 2, "explanation": "The study looks at the airway and soft tissues, so reduced technique shows them without burning them out."}, {"q": "This lateral neck shows prevertebral soft-tissue swelling. In an adult, the prevertebral soft tissue in front of C2 is normally no thicker than about:", "options": ["7 mm", "2 mm", "15 mm", "22 mm"], "answer_index": 0, "explanation": "Prevertebral tissue more than about 7 mm at C2 (or 22 mm at C6) suggests swelling such as a retropharyngeal abscess or hematoma."}, {"q": "Which sign on a lateral soft tissue neck suggests acute epiglottitis?", "options": ["Steeple sign", "Sail sign", "Double bubble sign", "Thumb sign"], "answer_index": 3, "explanation": "A swollen epiglottis looks like a thumb on the lateral view; the steeple sign of croup is seen on the AP view."}]}, {"modality": "Radiography", "region": "abdomen", "region_label": "Abdomen", "exam": "AP supine abdomen (KUB)", "image": {"file": "radiography__abdomen__ap-supine-abdomen.jpg", "caption": "KUB with a large left staghorn calculus.", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Medical_X-Ray_imaging_UEI07_nevit.jpg"}, "questions": [{"q": "For an AP supine abdomen (KUB), the central ray is directed to the level of the:", "options": ["xiphoid process", "iliac crests", "ASIS", "symphysis pubis"], "answer_index": 1, "explanation": "Centering at the iliac crests (about L4-L5) includes the kidneys through the symphysis pubis on most patients."}, {"q": "On this KUB, the dense branching opacity filling the left renal collecting system is most consistent with:", "options": ["Gallstones", "A staghorn calculus", "Pelvic phleboliths", "A calcified appendicolith"], "answer_index": 1, "explanation": "A large stone that fills the renal pelvis and calyces takes their branching shape and is called a staghorn calculus."}, {"q": "Which finding shows that an AP supine abdomen is NOT rotated?", "options": ["Both kidneys at the same level", "Iliac wings symmetric and spinous processes centered on the vertebrae", "Psoas shadows absent", "Ribs projected above the diaphragm"], "answer_index": 1, "explanation": "Symmetric iliac wings and centered spinous processes confirm a true AP; rotation makes one iliac wing look wider."}]}, {"modality": "Radiography", "region": "abdomen", "region_label": "Abdomen", "exam": "AP upright abdomen", "image": {"file": "radiography__abdomen__ap-upright-abdomen.jpg", "caption": "Upright abdomen with air-fluid levels from small bowel obstruction.", "credit": "James Heilman, MD", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Upright_X-ray_demonstrating_small_bowel_obstruction.jpg"}, "questions": [{"q": "For an AP erect abdomen, the central ray is centered:", "options": ["At the iliac crests", "At the symphysis pubis", "At the xiphoid process", "About 2 inches above the iliac crests so the diaphragm is included"], "answer_index": 3, "explanation": "Centering higher than for a supine KUB keeps the diaphragm on the image, where free air collects."}, {"q": "This upright image shows dilated small bowel loops with multiple air-fluid levels. This pattern most suggests:", "options": ["Small bowel obstruction", "Pneumoperitoneum", "Normal postprandial gas", "Ascites"], "answer_index": 0, "explanation": "Dilated loops with stepped air-fluid levels on an erect film are a classic sign of mechanical small bowel obstruction."}, {"q": "Why must the central ray be horizontal for an erect abdomen?", "options": ["To reduce magnification", "To lower gonadal dose", "Air-fluid levels are seen only when the beam is parallel to the fluid surface", "To show the kidneys better"], "answer_index": 2, "explanation": "A horizontal beam strikes the fluid surface edge-on, showing a sharp air-fluid line; an angled beam blurs it."}]}, {"modality": "Radiography", "region": "abdomen", "region_label": "Abdomen", "exam": "Left lateral decubitus abdomen", "image": {"file": "radiography__abdomen__left-lateral-decubitus-abdomen.jpg", "caption": "Left lateral decubitus abdomen showing free air beside the liver.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Freie_Luft_im_Abdomen_nach_PEG-Anlage_65W_-_CR_Linksseitenlage_-_001.jpg"}, "questions": [{"q": "Why is the left lateral decubitus preferred over the right lateral decubitus to look for free air?", "options": ["It is more comfortable for the patient", "It shows the spleen better", "Free air rises over the liver in the right flank, away from gastric air", "It reduces gonadal dose"], "answer_index": 2, "explanation": "With the right side up, free air collects against the dense liver, where it is easy to see and not confused with stomach gas."}, {"q": "A left lateral decubitus abdomen is technically which projection?", "options": ["AP (or PA) projection with a horizontal beam", "Lateral projection with a vertical beam", "Oblique projection", "Axial projection"], "answer_index": 0, "explanation": "The patient lies on the left side and the horizontal beam passes front to back, so it is named an AP projection in the decubitus position."}, {"q": "On a left lateral decubitus like this one, which area must be included on the image?", "options": ["Only the pelvis", "The left lung apex", "The symphysis pubis only", "The upside (right) flank and diaphragm"], "answer_index": 3, "explanation": "Free air collects at the highest point, the right flank and under the right hemidiaphragm, so that area must be on the image."}]}, {"modality": "Radiography", "region": "abdomen", "region_label": "Abdomen", "exam": "Acute abdomen series", "image": {"file": "radiography__abdomen__acute-abdomen-series.jpg", "caption": "Supine and left lateral decubitus abdomen in small bowel obstruction.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Mechanischer_Duenndarmileus_43M_-_CR_ap_und_linke_Seitenlage_-_001.jpg"}, "questions": [{"q": "A three-way acute abdomen series usually consists of:", "options": ["AP supine abdomen only", "AP supine abdomen, AP erect (or left lateral decubitus) abdomen, and PA erect chest", "Three lateral abdomens", "Right and left oblique abdomens"], "answer_index": 1, "explanation": "The supine shows gas pattern, the erect or decubitus shows air-fluid levels and free air, and the chest shows free air and chest causes of pain."}, {"q": "On an acute abdomen series like this one, which images can show air-fluid levels?", "options": ["Only the supine abdomen", "Only those taken with a horizontal beam (erect or decubitus)", "Any image, whatever the beam direction", "None of them"], "answer_index": 1, "explanation": "Fluid levels need a horizontal beam; the supine AP with a vertical beam shows gas pattern but not fluid levels."}, {"q": "A patient arrives for an acute abdomen series in a wheelchair. Which projections are usually taken first?", "options": ["The supine abdomen", "The decubitus abdomen", "Any order, since timing does not matter", "The erect projections"], "answer_index": 3, "explanation": "Doing the erect views first, while the patient is already upright, gives free air time to rise and avoids extra transfers."}]}, {"modality": "Radiography", "region": "abdomen", "region_label": "Abdomen", "exam": "Upper GI and small bowel series", "image": {"file": "radiography__abdomen__upper-gi-and-small-bowel-series.jpg", "caption": "Upper GI series image of the barium-filled stomach.", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Radiology_0005_Nevit.jpg"}, "questions": [{"q": "Routine patient preparation for an upper GI series is usually:", "options": ["NPO for about 8 hours before the exam", "A cleansing enema the night before", "Clear liquids up to 30 minutes before", "No preparation"], "answer_index": 0, "explanation": "An empty stomach allows the barium to coat the mucosa without food mimicking filling defects."}, {"q": "During a double-contrast upper GI, gas-producing crystals are given to:", "options": ["Coat the esophagus", "Speed gastric emptying", "Distend the stomach with gas for mucosal detail", "Reduce nausea"], "answer_index": 2, "explanation": "The crystals release carbon dioxide, which distends the stomach so the thin barium coat shows mucosal detail."}, {"q": "Glucagon is sometimes given during upper GI or small bowel studies to:", "options": ["Speed peristalsis", "Prevent contrast reactions", "Relax the smooth muscle of the GI tract", "Coat the mucosa"], "answer_index": 2, "explanation": "Glucagon makes the bowel hypotonic, which reduces spasm and helps distension for double-contrast images."}]}, {"modality": "Radiography", "region": "abdomen", "region_label": "Abdomen", "exam": "Contrast enema", "image": {"file": "radiography__abdomen__contrast-enema.jpg", "caption": "Double-contrast barium enema.", "credit": "Glitzy queen00 at English Wikipedia", "license": "Public domain", "page_url": "https://commons.wikimedia.org/wiki/File:Human_intestinal_tract,_as_imaged_via_double-contrast_barium_enema.jpg"}, "questions": [{"q": "A double-contrast barium enema, like this one, is mainly preferred over a single-contrast study for:", "options": ["Mucosal detail, such as small polyps", "Large bowel obstruction", "Suspected perforation", "Reducing an intussusception"], "answer_index": 0, "explanation": "A thin barium coat with air distension shows the mucosal surface, so small polyps and inflammatory changes are easier to see."}, {"q": "During a barium enema, which anterior oblique best opens the right colic (hepatic) flexure?", "options": ["LAO", "LPO", "Left lateral rectum", "RAO"], "answer_index": 3, "explanation": "The RAO opens the hepatic flexure and shows the ascending colon and cecum; the LAO opens the splenic flexure."}, {"q": "Which condition is a contraindication to a barium enema?", "options": ["Constipation", "Suspected toxic megacolon", "Age over 50", "History of colon polyps"], "answer_index": 1, "explanation": "A barium enema in toxic megacolon risks perforation, so the study is avoided or replaced by other imaging."}]}, {"modality": "Radiography", "region": "abdomen", "region_label": "Abdomen", "exam": "Cystography and retrograde urography", "image": {"file": "radiography__abdomen__cystography-and-retrograde-urography.jpg", "caption": "Cystogram with the bladder filled with contrast.", "credit": "Lucien Monfils", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Cysto.jpg"}, "questions": [{"q": "In a retrograde cystogram like this one, contrast reaches the bladder by:", "options": ["Intravenous injection", "Gravity drip through a urethral catheter", "Oral ingestion", "Percutaneous injection into the kidney"], "answer_index": 1, "explanation": "Retrograde means against the normal flow; diluted contrast is run in through a catheter rather than excreted by the kidneys."}, {"q": "Why are 45-60 degree posterior oblique images taken during cystography?", "options": ["To show the kidneys", "To lower dose", "To show the urethra in a female", "To show the posterolateral bladder walls and the ureterovesical junctions"], "answer_index": 3, "explanation": "The obliques show the bladder walls in profile and help show reflux into the distal ureters."}, {"q": "For the AP projection of a cystogram, the central ray is typically angled:", "options": ["10-15 degrees caudad", "10-15 degrees cephalad", "45 degrees caudad", "Perpendicular to the IR"], "answer_index": 0, "explanation": "A caudal angle projects the symphysis pubis below the bladder base so the bladder neck and distal ureters are not obscured."}]}, {"modality": "Radiography", "region": "abdomen", "region_label": "Abdomen", "exam": "ERCP and surgical cholangiography", "image": {"file": "radiography__abdomen__ercp-and-surgical-cholangiography.jpg", "caption": "ERCP showing opacified bile and pancreatic ducts with gallstones.", "credit": "J. Guntau at German Wikipedia", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:ERCP_Roentgen.jpg"}, "questions": [{"q": "In an ERCP such as this one, contrast is introduced:", "options": ["By intravenous injection", "Through a T-tube placed at surgery", "Through a cannula passed via a duodenoscope into the ampulla of Vater", "By percutaneous needle into the liver"], "answer_index": 2, "explanation": "The endoscope (seen curving into the duodenum) is used to cannulate the ampulla and fill the biliary and pancreatic ducts in retrograde fashion."}, {"q": "A postoperative (T-tube) cholangiogram is mainly performed to:", "options": ["Measure gallbladder ejection fraction", "Visualize the pancreas directly", "Check for retained stones and ductal patency after biliary surgery", "Assess renal function"], "answer_index": 2, "explanation": "Contrast injected through the T-tube left in the common bile duct shows retained stones and confirms free flow into the duodenum."}, {"q": "Which complication of ERCP is the most common and important for the team to watch for?", "options": ["Pancreatitis", "Hyperthyroidism", "Kidney stone formation", "Pneumothorax"], "answer_index": 0, "explanation": "Cannulating and injecting the pancreatic duct can trigger post-ERCP pancreatitis, its most common serious complication."}]}, {"modality": "Radiography", "region": "pelvis", "region_label": "Pelvis & Hips", "exam": "AP pelvis", "image": {"file": "radiography__pelvis__ap-pelvis.jpg", "caption": "Normal AP pelvis of a young adult male.", "credit": "Department of Radiology, UC San Diego Health", "license": "Public domain", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_the_pelvis_of_an_18_year_old_male_-_case_1_-_anteroposterior.jpg"}, "questions": [{"q": "On an AP pelvis with correct 15-20 degree internal rotation, the lesser trochanters should appear:", "options": ["very prominent on both sides", "superimposed on the femoral heads", "absent or only slightly visible", "projected above the iliac crests"], "answer_index": 2, "explanation": "Internal rotation turns the lesser trochanters posteriorly, so they are barely visible or hidden; a prominent lesser trochanter suggests external rotation."}, {"q": "For an AP pelvis, the central ray is directed:", "options": ["At the iliac crests", "At the symphysis pubis", "2 inches above the ASIS", "Midway between the ASIS and the symphysis pubis"], "answer_index": 3, "explanation": "Centering midway between the level of the ASIS and the symphysis (about 2 inches below the ASIS) includes the whole pelvis and proximal femora."}, {"q": "When should the feet NOT be internally rotated for an AP pelvis?", "options": ["When the patient is elderly", "When a hip fracture or dislocation is suspected", "When a grid is used", "When the patient is female"], "answer_index": 1, "explanation": "Rotating a fractured or dislocated hip can displace fragments and cause pain, so trauma patients are imaged as they are."}]}, {"modality": "Radiography", "region": "pelvis", "region_label": "Pelvis & Hips", "exam": "AP hip", "image": {"file": "radiography__pelvis__ap-hip.jpg", "caption": "AP hip radiograph of an adult.", "credit": "Mikael Häggström, M.D.", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_a_normal_hip.jpg"}, "questions": [{"q": "On an AP hip with correct internal rotation, the greater trochanter appears:", "options": ["Superimposed on the femoral neck", "In profile on the lateral side", "Hidden behind the femoral head", "Projected above the acetabulum"], "answer_index": 1, "explanation": "Internal rotation places the femoral neck parallel to the IR and shows the greater trochanter in profile laterally."}, {"q": "For an AP hip on a patient with a hip prosthesis, the image must include:", "options": ["Only the acetabulum", "Only the femoral head", "The opposite hip", "The entire prosthesis and surrounding cement"], "answer_index": 3, "explanation": "Loosening or fracture can occur anywhere along the implant, so the whole device and its cement must be shown."}, {"q": "A routine AP hip like this one is typically done with which setup?", "options": ["40-inch (100 cm) SID with a grid and the IR lengthwise", "72-inch SID with no grid", "40-inch SID with no grid and the IR crosswise", "30-inch SID with a grid"], "answer_index": 0, "explanation": "The hip is thick enough to need a grid, and a lengthwise IR at 40 inches covers the acetabulum and proximal femur."}]}, {"modality": "Radiography", "region": "pelvis", "region_label": "Pelvis & Hips", "exam": "Unilateral and bilateral frog-leg (non-trauma)", "image": {"file": "radiography__pelvis__unilateral-and-bilateral-frog-leg.jpg", "caption": "Frog-leg lateral hip showing a slipped capital femoral epiphysis.", "credit": "Mikir at English Wikipedia", "license": "Public domain", "page_url": "https://commons.wikimedia.org/wiki/File:SCFE_FROG_B&W.jpg"}, "questions": [{"q": "For the bilateral frog-leg (modified Cleaves), the femurs are abducted about:", "options": ["10 degrees from vertical", "90 degrees from vertical", "40-45 degrees from vertical", "They are not abducted"], "answer_index": 2, "explanation": "Abducting the flexed thighs about 40-45 degrees from vertical gives a lateral view of the femoral heads and necks."}, {"q": "This frog-leg image shows a slipped capital femoral epiphysis. Why is the frog-leg lateral valuable in SCFE?", "options": ["It lowers dose compared with the AP", "It shows the SI joints", "It shows posterior slippage of the epiphysis that may be missed on the AP", "It is required for every adult hip"], "answer_index": 2, "explanation": "The epiphysis usually slips posteriorly and medially, which is easier to see on a lateral than on the AP."}, {"q": "On a frog-leg lateral, which change gives the least foreshortening of the femoral necks?", "options": ["Abducting the femurs only about 20-30 degrees from vertical", "Maximum abduction to the table", "Keeping the legs straight", "Internally rotating the legs 15 degrees"], "answer_index": 0, "explanation": "Less abduction shows the femoral necks with less foreshortening, at the cost of more foreshortening of the proximal femora."}]}, {"modality": "Radiography", "region": "pelvis", "region_label": "Pelvis & Hips", "exam": "Cross-table axiolateral hip (Danelius-Miller)", "image": {"file": "radiography__pelvis__cross-table-axiolateral-hip.jpg", "caption": "Cross-table axiolateral (lateral) hip radiograph.", "credit": "Mikael Häggström, M.D.", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_idiopathic_avascular_necrosis_of_the_femoral_head_-_Lateral.jpg"}, "questions": [{"q": "A trauma patient arrives with a shortened, externally rotated leg. Which lateral hip projection is appropriate?", "options": ["Unilateral frog-leg (modified Cleaves)", "Bilateral frog-leg", "Cross-table axiolateral (Danelius-Miller)", "PA oblique"], "answer_index": 2, "explanation": "Frog-leg views require moving the leg and are contraindicated with suspected fracture; the cross-table axiolateral leaves the affected leg in place."}, {"q": "For the axiolateral (Danelius-Miller) hip, the unaffected leg is:", "options": ["Left flat on the table", "Internally rotated next to the affected leg", "Abducted 45 degrees on the table", "Flexed and raised so it is out of the beam"], "answer_index": 3, "explanation": "Raising the unaffected thigh moves it out of the horizontal beam's path to the affected hip."}, {"q": "For the Danelius-Miller projection, the central ray is directed:", "options": ["Vertically through the greater trochanter", "Horizontally, perpendicular to the femoral neck and the IR", "45 degrees cephalad", "Parallel to the femoral neck"], "answer_index": 1, "explanation": "The IR is placed parallel to the femoral neck and the horizontal CR is perpendicular to both, giving a true lateral of the neck as seen here."}]}, {"modality": "Radiography", "region": "pelvis", "region_label": "Pelvis & Hips", "exam": "Inlet and outlet projections", "image": {"file": "radiography__pelvis__inlet-and-outlet-projections.jpg", "caption": "Pelvis inlet view with a left inferior pubic ramus fracture.", "credit": "Cerevisae", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Pelvis_inlet_view_showing_fracture_of_the_left_ischium.jpg"}, "questions": [{"q": "For the AP axial outlet projection of the pelvis in a male patient, the CR is angled:", "options": ["20-35 degrees cephalad", "40 degrees caudad", "15 degrees caudad", "perpendicular to the IR"], "answer_index": 0, "explanation": "The outlet view uses a cephalad angle (about 20-35 degrees for males, 30-45 for females) to show the pubic and ischial rami."}, {"q": "Inlet and outlet projections are most commonly ordered to evaluate:", "options": ["Hip arthroplasty follow-up", "Pelvic ring trauma", "Early pregnancy", "Bone age"], "answer_index": 1, "explanation": "The two angled views show the pelvic ring from above and from the front, which shows how fracture fragments are displaced."}, {"q": "An inlet view like this one is mainly used to assess:", "options": ["The SI joint spaces only", "The femoral necks", "The coccyx", "The pelvic ring for anterior or posterior displacement of fractures"], "answer_index": 3, "explanation": "Looking down through the pelvic ring shows inward or outward and front-to-back shift of fracture fragments."}]}, {"modality": "Radiography", "region": "pelvis", "region_label": "Pelvis & Hips", "exam": "Judet (acetabulum) obliques", "image": {"file": "radiography__pelvis__judet-obliques.jpg", "caption": "Judet oblique (RPO, left side up) showing the left obturator foramen.", "credit": "Cerevisae", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Judet_view_right_posterior_oblique_(RPO)_and_left_hip_elevated.jpg"}, "questions": [{"q": "In a 45-degree posterior oblique Judet with the affected side UP, which acetabular parts are best shown on the affected side?", "options": ["Anterior (iliopubic) column and posterior rim", "Posterior (ilioischial) column and anterior rim", "Iliac wing only", "SI joint only"], "answer_index": 0, "explanation": "The upside view is the obturator oblique, which shows the anterior column and posterior rim; the downside view shows the opposite."}, {"q": "How much is the pelvis rotated for the Judet projections?", "options": ["15 degrees", "30 degrees", "45 degrees", "60 degrees"], "answer_index": 2, "explanation": "Each Judet view rotates the pelvis 45 degrees toward or away from the affected side."}, {"q": "On an obturator oblique like this one, the obturator foramen of the side being evaluated appears:", "options": ["Closed and foreshortened", "Superimposed on the femoral head", "Open, seen nearly en face", "Hidden behind the sacrum"], "answer_index": 2, "explanation": "The obturator oblique opens the obturator foramen, while the iliac oblique shows the iliac wing en face and closes the foramen."}]}, {"modality": "Radiography", "region": "pelvis", "region_label": "Pelvis & Hips", "exam": "Sacroiliac joints", "image": {"file": "radiography__pelvis__sacroiliac-joints.jpg", "caption": "Radiograph of the sacroiliac joints showing sacroiliitis.", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Rad_1300095.JPG"}, "questions": [{"q": "For the AP axial projection of the SI joints, the central ray is angled:", "options": ["30-35 degrees cephalad", "30-35 degrees caudad", "15 degrees caudad", "Perpendicular to the IR"], "answer_index": 0, "explanation": "A cephalad angle of about 30 degrees for males and 35 for females opens the obliquely oriented SI joints."}, {"q": "Why is the AP axial SI joint angle usually greater for women (about 35 degrees) than for men (about 30)?", "options": ["Women have narrower SI joints", "To lower ovarian dose", "Women are imaged prone", "The female pelvis typically has greater anterior tilt"], "answer_index": 3, "explanation": "Greater pelvic tilt in women changes the angle of the joints, so a steeper cephalad angle is needed to open them."}, {"q": "This image shows bilateral sacroiliitis. Symmetric bilateral sacroiliitis is classically associated with:", "options": ["Osteoarthritis of the hip", "Ankylosing spondylitis", "Paget disease", "Gout"], "answer_index": 1, "explanation": "Ankylosing spondylitis typically starts with symmetric erosion and sclerosis of both SI joints before involving the spine."}]}, {"modality": "Radiography", "region": "pelvis", "region_label": "Pelvis & Hips", "exam": "Hysterosalpingography", "image": {"file": "radiography__pelvis__hysterosalpingography.jpg", "caption": "Normal hysterosalpingogram.", "credit": "Jmarchn", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Hysterosalpingography_Normal.png"}, "questions": [{"q": "During hysterosalpingography, contrast is introduced:", "options": ["By intravenous injection", "Through a catheter or cannula placed in the cervical canal", "By mouth", "Through a urethral catheter"], "answer_index": 1, "explanation": "Contrast is injected through the cervix to fill the uterine cavity and fallopian tubes."}, {"q": "HSG is usually scheduled:", "options": ["Right before menses begin", "During heavy menstrual bleeding", "In the middle of the luteal phase", "About 7-10 days after menses begin, before ovulation"], "answer_index": 3, "explanation": "Timing after bleeding stops but before ovulation reduces the chance of early pregnancy and of pushing menstrual debris into the tubes."}, {"q": "On an HSG like this one, contrast spilling freely into the peritoneal cavity indicates:", "options": ["Patent fallopian tubes", "Blocked fallopian tubes", "Uterine perforation", "Hydrosalpinx"], "answer_index": 0, "explanation": "Free spill from the tube ends shows the tubes are open; blocked tubes stop the contrast or show a dilated, closed end."}]}, {"modality": "Radiography", "region": "spine", "region_label": "Spine", "exam": "Cervical spine (AP axial, open-mouth, lateral, obliques, swimmer's)", "image": {"file": "radiography__spine__cervical-spine.jpg", "caption": "AP open-mouth (odontoid) projection of C1-C2 in a young adult", "credit": "Staff at the Department of Radiology, UC San Diego Health", "license": "Public domain", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_the_cervical_spine_of_a_20_year_old_male_-_odontoid.jpg"}, "questions": [{"q": "For an AP open-mouth projection of C1-C2 like this one, which two landmarks are aligned perpendicular to the receptor?", "options": ["Lower edge of the upper incisors and the base of the skull (mastoid tips)", "Glabella and mentum", "Acanthion and EAM", "Nasion and inion"], "answer_index": 0, "explanation": "Aligning the lower margin of the upper incisors with the mastoid tips clears the dens and C1-C2 from the teeth and skull base."}, {"q": "For a swimmer's (cervicothoracic) lateral, the central ray is centered to:", "options": ["C4, at the thyroid cartilage", "T4, at the sternal angle", "C7-T1, about 1 inch above the jugular notch", "C1, at the mastoid tip"], "answer_index": 2, "explanation": "The swimmer's lateral targets the cervicothoracic junction, with the arm nearest the IR raised and the opposite shoulder lowered."}, {"q": "For anterior oblique (RAO or LAO) cervical spine projections, the central ray is angled:", "options": ["15-20 degrees cephalad", "15-20 degrees caudad", "Perpendicular, with no angle", "30 degrees caudad"], "answer_index": 1, "explanation": "Anterior obliques use a caudad angle and posterior obliques a cephalad angle so the CR follows the intervertebral foramina."}]}, {"modality": "Radiography", "region": "spine", "region_label": "Spine", "exam": "Thoracic spine (AP, lateral)", "image": {"file": "radiography__spine__thoracic-spine.jpg", "caption": "AP thoracic spine radiograph", "credit": "IanWhyte", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Thoracic_spine_AP.png"}, "questions": [{"q": "On an AP thoracic spine like this one, which finding shows the patient was not rotated?", "options": ["Ribs projected entirely below the diaphragm", "Clavicles projected above the lung apices", "Intervertebral foramina open on one side", "Spinous processes centered between the pedicles, with the SC joints equidistant from the spine"], "answer_index": 3, "explanation": "Equal distances from the spinous processes to the pedicles, and symmetric SC joints, mean the thorax was flat against the table."}, {"q": "For a lateral thoracic spine, a lead mat placed on the table behind the patient is used to:", "options": ["Shield the patient's gonads", "Act as a compensating filter for the upper thorax", "Absorb scatter and improve image quality", "Replace the grid"], "answer_index": 2, "explanation": "The lateral thorax produces a lot of scatter; lead behind the patient keeps table scatter from reaching the IR."}, {"q": "For an AP thoracic spine, the central ray is centered to:", "options": ["T7, about 3-4 inches (8-10 cm) below the jugular notch", "T4 at the level of the sternal angle", "T10 at the xiphoid tip", "T12, about 1 inch above the iliac crest"], "answer_index": 0, "explanation": "T7 lies about midway between the jugular notch and the xiphoid, centering all 12 thoracic vertebrae."}]}, {"modality": "Radiography", "region": "spine", "region_label": "Spine", "exam": "Lumbar spine (AP, lateral, obliques, L5-S1 spot)", "image": {"file": "radiography__spine__lumbar-spine.jpg", "caption": "Lateral lumbar spine radiograph", "credit": "FitBro", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Lateral_lumbar_x_ray.jpg"}, "questions": [{"q": "Which projection best demonstrates the L5-S1 zygapophyseal joint?", "options": ["45-degree posterior oblique", "Lateral with 15-degree caudad angle", "AP with 30-degree cephalad angle", "30-degree posterior oblique"], "answer_index": 3, "explanation": "The L5-S1 zygapophyseal joint lies at a smaller angle to the midsagittal plane, so about 30 degrees of obliquity opens it; L1-L4 need 45 degrees."}, {"q": "On a lateral lumbar spine like this one, a patient with wide hips and a narrow waist cannot have the spine supported parallel to the table. The CR should be:", "options": ["Angled 5-8 degrees cephalad", "Angled 5-8 degrees caudad", "Kept perpendicular and the SID shortened", "Angled 15 degrees cephalad"], "answer_index": 1, "explanation": "A sagging spine slopes toward the feet; a slight caudad angle brings the CR perpendicular to the spine so the disk spaces open."}, {"q": "On a lateral lumbar spine like this one, which finding shows the patient was not rotated?", "options": ["The spinous processes are centered between the pedicles", "The posterior margins of each vertebral body superimpose", "The sacroiliac joints are open", "The transverse processes are seen in profile on both sides"], "answer_index": 1, "explanation": "In a true lateral, the posterior body margins line up as single edges; double contours mean rotation."}]}, {"modality": "Radiography", "region": "spine", "region_label": "Spine", "exam": "Sacrum and coccyx", "image": {"file": "radiography__spine__sacrum-and-coccyx.jpg", "caption": "Lateral sacrum and coccyx radiograph showing a coccygeal fracture", "credit": "Jmarchn", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_coccyx_fracture.jpg"}, "questions": [{"q": "Why are the AP axial sacrum and AP axial coccyx usually taken as separate exposures?", "options": ["The coccyx needs a horizontal beam", "The sacrum must be taken PA", "Both require the patient to be prone", "They need opposite CR angles: cephalad for the sacrum, caudad for the coccyx"], "answer_index": 3, "explanation": "The sacrum uses about 15 degrees cephalad and the coccyx about 10 degrees caudad, so one exposure cannot show both without distortion."}, {"q": "On a true lateral sacrum and coccyx like this one, correct positioning is confirmed when the:", "options": ["Posterior margins of the greater sciatic notches and the femoral heads superimpose", "Iliac crests appear at different levels", "Obturator foramina are open and symmetric", "Sacroiliac joints are seen in profile"], "answer_index": 0, "explanation": "Superimposed sciatic notches and femoral heads show the pelvis is not rotated, giving a true lateral of the sacrum and coccyx."}, {"q": "Before sacrum and coccyx radiography, the patient should ideally:", "options": ["Drink 500 mL of water to fill the bladder", "Receive IV contrast", "Empty the bladder, with the lower colon free of gas and feces", "Fast for 12 hours to clear the stomach"], "answer_index": 2, "explanation": "A full bladder and bowel contents overlie the sacrum and coccyx and obscure them."}]}, {"modality": "Radiography", "region": "spine", "region_label": "Spine", "exam": "Scoliosis series", "image": {"file": "radiography__spine__scoliosis-series.jpg", "caption": "Frontal thoracolumbar spine radiograph showing scoliosis (cropped to remove the institutional header)", "credit": "Celica gurlz (Wikimedia Commons user)", "license": "Public domain", "page_url": "https://commons.wikimedia.org/wiki/File:Scoliosis_X-ray.jpg"}, "questions": [{"q": "Scoliosis series are taken with the patient erect mainly because:", "options": ["Weight-bearing shows the true degree of curvature", "Supine positioning increases breast dose", "The grid cannot be used supine", "Erect positioning reduces the curvature for easier measurement"], "answer_index": 0, "explanation": "Gravity and weight-bearing show the curve as it is in daily life; supine images can understate it."}, {"q": "In the Ferguson method for scoliosis, the second image is taken with:", "options": ["The patient bending maximally toward the concave side", "A block under the foot on the concave side", "A 3-4 inch block under the foot or hip on the convex side of the curve", "The patient supine with knees flexed"], "answer_index": 2, "explanation": "Elevating the convex side helps distinguish the primary (structural) curve from the compensatory curve."}, {"q": "On a frontal scoliosis image like this one, the Cobb angle is drawn between lines along the:", "options": ["Spinous processes of the apex vertebra", "Superior endplate of the upper end vertebra and inferior endplate of the lower end vertebra", "Iliac crests and the shoulders", "Pedicles of the apex vertebra"], "answer_index": 1, "explanation": "The Cobb angle uses the most tilted vertebrae at each end of the curve; the angle between their endplate lines measures curve severity."}]}, {"modality": "Radiography", "region": "spine", "region_label": "Spine", "exam": "Flexion and extension laterals", "image": {"file": "radiography__spine__flexion-and-extension-laterals.jpg", "caption": "Lateral cervical spine in flexion and extension", "credit": "Stillwaterising (derivative montage)", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Cervical_XRayFlexionExtension.jpg"}, "questions": [{"q": "Lateral flexion and extension views of the spine are primarily performed to evaluate:", "options": ["Bone mineral density", "Disk herniation", "Intervertebral foramina", "Abnormal vertebral motion or ligamentous instability"], "answer_index": 3, "explanation": "Comparing alignment at the limits of motion shows subluxation, instability, or motion at a fusion site that a neutral lateral can miss."}, {"q": "Before cervical flexion and extension views on a trauma patient, the technologist should:", "options": ["Remove the collar and have the patient flex until pain begins", "Flex and extend the patient's head for them to ensure full range", "Confirm that a fracture has been ruled out and the physician has approved the movement", "Use a 40-inch SID so the exposures can be quicker"], "answer_index": 2, "explanation": "Moving an unstable spine can cause cord injury, so these views are done only after a neutral series is cleared."}, {"q": "For flexion and extension laterals like these, the patient should move the head:", "options": ["Only as far as they can actively and comfortably, without help", "To full range, assisted by the technologist", "Into flexion only, then rotate for the second view", "While breathing deeply to blur the shoulders"], "answer_index": 0, "explanation": "Active motion within the patient's own limits gives useful information without the risk of forcing an unstable segment."}]}, {"modality": "Radiography", "region": "spine", "region_label": "Spine", "exam": "Myelography", "image": {"file": "radiography__spine__myelography.jpg", "caption": "Oblique lumbar myelogram with intrathecal contrast outlining the thecal sac and nerve root sleeves", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Myelographie_schraeg.jpg"}, "questions": [{"q": "Which contrast agent is used for a modern lumbar myelogram like this one?", "options": ["Barium sulfate suspension", "Ionic, high-osmolar iodinated contrast", "Gadolinium at standard IV dose", "Nonionic, water-soluble iodinated contrast approved for intrathecal use"], "answer_index": 3, "explanation": "Only nonionic iodinated agents labeled for intrathecal use (such as iohexol) are injected into the subarachnoid space; ionic agents can cause seizures and severe reactions."}, {"q": "For a lumbar myelogram, the needle is usually placed at:", "options": ["The T12-L1 interspace", "The L2-L3 or L3-L4 interspace", "The L5-S1 interspace only", "The C1-C2 interspace"], "answer_index": 1, "explanation": "Puncture below the conus medullaris (about L1-L2) avoids the spinal cord; C1-C2 is a lateral approach used for cervical studies."}, {"q": "After a myelogram with water-soluble contrast, the patient is kept with the head elevated mainly to:", "options": ["Speed absorption of contrast into the kidneys", "Keep contrast from flowing into the intracranial space", "Prevent air embolism", "Reduce bleeding at the puncture site"], "answer_index": 1, "explanation": "Contrast reaching the head raises the risk of headache and seizures, so the head stays elevated and the patient is hydrated."}]}, {"modality": "Radiography", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Fingers and thumb", "image": {"file": "radiography__upper_extremity__fingers-and-thumb.jpg", "caption": "PA projection of the thumb", "credit": "Staff at the Department of Radiology, UC San Diego Health", "license": "Public domain", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_the_thumb_of_an_18_year_old_male_-_posteroanterior.jpg"}, "questions": [{"q": "For a PA thumb like this one, the image must include:", "options": ["Only the phalanges and IP joint", "All five digits", "The distal radius and ulna", "The entire first metacarpal and the trapezium"], "answer_index": 3, "explanation": "Thumb projections cover the distal phalanx through the first CMC joint and trapezium, where many thumb injuries occur."}, {"q": "For oblique and lateral finger projections, the affected digit is kept parallel to the IR in order to:", "options": ["Avoid foreshortening and keep the IP joints open", "Superimpose the phalanges on the metacarpals", "Reduce the exposure needed", "Place the digit in contact with the next finger"], "answer_index": 0, "explanation": "A finger angled toward the IR is foreshortened and its joints close; supporting it parallel shows true length and open joints."}, {"q": "The modified Robert method shows the first carpometacarpal joint using an AP thumb with the CR angled:", "options": ["15 degrees distally, toward the fingertip", "45 degrees proximally", "15 degrees proximally, toward the wrist", "Perpendicular to the first MCP joint"], "answer_index": 2, "explanation": "The 15-degree proximal angle with the hand hyperpronated opens the first CMC joint, useful for Bennett fractures and arthritis."}]}, {"modality": "Radiography", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Hand (PA, oblique, lateral)", "image": {"file": "radiography__upper_extremity__hand.jpg", "caption": "PA oblique hand of a child, with open growth plates", "credit": "Staff at the Department of Radiology, UC San Diego Health", "license": "Public domain", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_the_hand_of_a_6_year_old_male_-_oblique.jpg"}, "questions": [{"q": "For the PA oblique hand shown, where is the central ray directed?", "options": ["The third metacarpophalangeal (MCP) joint", "The second proximal interphalangeal joint", "The midcarpal area", "The radial styloid"], "answer_index": 0, "explanation": "The CR centers at the third MCP joint for PA and PA oblique hand projections, covering fingertips to distal radius and ulna."}, {"q": "On the pediatric hand shown, the thin lucent lines near the ends of the phalanges and metacarpals are:", "options": ["Fracture lines", "Mach band artifacts", "Normal open growth plates (physes)", "Periosteal reaction"], "answer_index": 2, "explanation": "Children have open physes that appear as lucent bands; they should not be mistaken for fractures."}, {"q": "On a correctly rotated PA oblique hand like this one, the midshafts of the third through fifth metacarpals should:", "options": ["Be completely superimposed", "Overlap only slightly; heavy overlap means over-rotation", "Be completely separated", "Overlap the second metacarpal"], "answer_index": 1, "explanation": "At 45 degrees there is minimal overlap of metacarpals 3-5; too much overlap means the hand was rotated past 45 degrees."}]}, {"modality": "Radiography", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Wrist (PA, oblique, lateral, ulnar deviation, Gaynor-Hart)", "image": {"file": "radiography__upper_extremity__wrist.jpg", "caption": "Normal PA wrist", "credit": "Mikael Häggström, M.D.", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_normal_wrist_by_dorsoplantar_projection.jpg"}, "questions": [{"q": "Which tangential projection shows the carpal canal (carpal tunnel)?", "options": ["Stecher", "Norgaard", "Coyle", "Gaynor-Hart"], "answer_index": 3, "explanation": "The Gaynor-Hart method angles the CR about 25-30 degrees to the long axis of the hand to show the carpal canal."}, {"q": "In the Stecher method for the scaphoid, the wrist is PA in ulnar deviation and the CR is angled:", "options": ["20 degrees toward the fingers", "45 degrees toward the elbow", "20 degrees toward the elbow", "Perpendicular, with the hand in radial deviation"], "answer_index": 2, "explanation": "The 20-degree angle toward the elbow (or the IR raised 20 degrees) puts the beam perpendicular to the scaphoid for a less foreshortened view."}, {"q": "For the PA wrist shown, the fingers are slightly flexed (arched) in order to:", "options": ["Bring the wrist and carpals into close contact with the IR", "Open the intercarpal joint spaces fully", "Superimpose the radius and ulna", "Show the carpal canal"], "answer_index": 0, "explanation": "Arching the fingers lowers the carpal region onto the IR, reducing OID and improving detail."}]}, {"modality": "Radiography", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Forearm", "image": {"file": "radiography__upper_extremity__forearm.jpg", "caption": "AP forearm including the wrist and elbow joints", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Medical_X-Ray_imaging_UHU07_nevit.jpg"}, "questions": [{"q": "For forearm projections, the shoulder is lowered to the level of the elbow in order to:", "options": ["Reduce the OID of the hand", "Open the elbow joint space", "Superimpose the radius and ulna", "Place the humerus and forearm in the same plane, preventing rotation"], "answer_index": 3, "explanation": "If the shoulder is higher than the elbow, the proximal forearm rotates and the radius and ulna are distorted."}, {"q": "On an AP forearm like this one, the anode heel effect is best used by placing the:", "options": ["Wrist toward the cathode end", "Elbow toward the cathode end of the tube", "Elbow toward the anode end", "Forearm perpendicular to the tube axis"], "answer_index": 1, "explanation": "The thicker proximal forearm goes under the stronger cathode side, giving more uniform density from elbow to wrist."}, {"q": "On a correctly positioned AP forearm like this one, the proximal radius shows:", "options": ["The radius crossing the ulna at the midshaft", "Slight superimposition of the radial head, neck, and tuberosity over the ulna", "The radial head completely free of the ulna", "The olecranon process in profile"], "answer_index": 1, "explanation": "With the hand supinated and epicondyles parallel to the IR, only slight overlap of the proximal radius on the ulna is expected."}]}, {"modality": "Radiography", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Elbow (AP, lateral, obliques, Coyle)", "image": {"file": "radiography__upper_extremity__elbow.jpg", "caption": "Normal lateral elbow flexed 90 degrees", "credit": "Mikael Häggström, M.D.", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_normal_elbow_by_lateral_projection.jpg"}, "questions": [{"q": "On a true lateral elbow like this one, the elbow is flexed 90 degrees and the humeral epicondyles are:", "options": ["Parallel to the IR", "Rotated 45 degrees medially", "Rotated 45 degrees laterally", "Perpendicular to the IR"], "answer_index": 3, "explanation": "Epicondyles perpendicular to the IR, with 90-degree flexion, superimpose them and show the fat pads and olecranon in profile."}, {"q": "On a true lateral elbow, which appearance confirms correct positioning?", "options": ["Three concentric arcs formed by the trochlear sulcus, the capitulum and trochlea, and the trochlear notch", "The radial head free of the coronoid process", "The olecranon seen within the olecranon fossa", "The epicondyles separated by 2 cm"], "answer_index": 0, "explanation": "These concentric arcs appear only when the epicondyles are superimposed and the elbow is flexed 90 degrees."}, {"q": "For an AP elbow, the central ray is directed:", "options": ["Perpendicular to the olecranon process", "45 degrees toward the shoulder", "Perpendicular to the middle of the elbow joint, about 3/4 inch distal to the midpoint between the epicondyles", "Perpendicular to the medial epicondyle"], "answer_index": 2, "explanation": "The elbow joint lies slightly distal to the line between the epicondyles, so the CR is centered there with the arm extended and hand supinated."}]}, {"modality": "Radiography", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Humerus", "image": {"file": "radiography__upper_extremity__humerus.jpg", "caption": "AP humerus including the shoulder and elbow", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Medical_X-Ray_imaging_MXK06_nevit.jpg"}, "questions": [{"q": "An AP humerus like this one must include:", "options": ["Both the shoulder and elbow joints", "Only the joint closest to the injury", "The shoulder joint and clavicle only", "The mid-shaft only, collimated tightly"], "answer_index": 0, "explanation": "Long-bone images include both joints; for a long humerus, the IR is placed diagonally or a second image is taken."}, {"q": "For a transthoracic lateral humerus, the central ray is centered to the:", "options": ["Acromion of the unaffected side", "Mid-shaft of the humerus", "Surgical neck of the affected humerus", "Jugular notch"], "answer_index": 2, "explanation": "With the unaffected arm raised over the head, centering at the surgical neck shows the proximal humerus through the thorax."}, {"q": "On a rotational lateral humerus (epicondyles perpendicular to the IR), which structure is in profile?", "options": ["The greater tubercle, laterally", "The lesser tubercle, medially", "The coracoid process", "The olecranon process"], "answer_index": 1, "explanation": "Internal rotation to a lateral position turns the lesser tubercle into profile on the medial side of the proximal humerus."}]}, {"modality": "Radiography", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Shoulder (internal and external rotation, Grashey, scapular Y)", "image": {"file": "radiography__upper_extremity__shoulder.jpg", "caption": "Normal Grashey (AP glenoid) shoulder projection", "credit": "Mikael Häggström", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:Anteroposterior_glenoid_(Grashey_view)_X-ray_of_a_normal_shoulder.jpg"}, "questions": [{"q": "For a PA oblique (scapular Y) shoulder, the patient's body is rotated about:", "options": ["15-20 degrees, with the affected side away from the IR", "90 degrees, in a true lateral", "35-45 degrees, with the back toward the IR", "45-60 degrees, with the affected side toward the IR"], "answer_index": 3, "explanation": "A 45-60 degree anterior oblique turns the scapula lateral so it forms a Y with the acromion and coracoid."}, {"q": "A Hill-Sachs defect of the posterolateral humeral head is best shown on which AP shoulder projection?", "options": ["AP with external rotation", "AP with neutral rotation", "AP with internal rotation", "AP axial clavicle"], "answer_index": 2, "explanation": "Internal rotation turns the posterolateral humeral head into profile, where the compression defect from an anterior dislocation is seen."}, {"q": "On a scapular Y projection of an anteriorly dislocated shoulder, the humeral head appears:", "options": ["Anterior to the glenoid, beneath the coracoid process", "Centered over the junction of the Y", "Posterior, beneath the acromion", "Superior to the acromion"], "answer_index": 0, "explanation": "Normally the head overlies the center of the Y; an anterior dislocation moves it under the coracoid, toward the ribs."}]}, {"modality": "Radiography", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Clavicle and AC joints", "image": {"file": "radiography__upper_extremity__clavicle-and-ac-joints.jpg", "caption": "AP radiograph of the clavicle and shoulder girdle", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Medical_X-Ray_imaging_LIH05_nevit.jpg"}, "questions": [{"q": "A routine clavicle projection like this one must include:", "options": ["Only the lateral third and AC joint", "The clavicle and the entire humerus", "Both clavicles on one image", "The whole clavicle, from the AC joint to the SC joint"], "answer_index": 3, "explanation": "The full length of the clavicle and both of its joints are shown, since fractures most often occur in the middle third."}, {"q": "On a weight-bearing AC joint study, an acromioclavicular separation is shown by:", "options": ["Narrowing of the glenohumeral joint", "Widening of the AC joint and a greater coracoclavicular distance than on the other side", "Elevation of the scapula on the injured side only without the weights", "Superimposition of the clavicle and acromion"], "answer_index": 1, "explanation": "Comparing both sides under weight shows the distal clavicle riding higher when the AC and coracoclavicular ligaments are torn."}, {"q": "Compared with the AP clavicle, a PA clavicle gives:", "options": ["More magnification", "Sharper detail because of reduced OID", "A view of the scapula without the ribs", "Lower patient dose to the thyroid only"], "answer_index": 1, "explanation": "The clavicle is closer to the IR in the PA, reducing magnification and blur, though AP is easier for trauma patients."}]}, {"modality": "Radiography", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Toes and sesamoids", "image": {"file": "radiography__lower_extremity__toes-and-sesamoids.jpg", "caption": "AP toes centered on the first MTP joint, showing hallux rigidus and the hallux sesamoids", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Hallux_rigidus_82W_-_CR_ap_-_001.jpg"}, "questions": [{"q": "For the AP toes, the CR is angled 10-15 degrees toward the:", "options": ["Toes, to open the tarsometatarsal joints", "Medial malleolus", "Lateral malleolus", "Calcaneus, to open the interphalangeal and MTP joints"], "answer_index": 3, "explanation": "Angling toward the heel puts the CR perpendicular to the phalanges and opens their joints; a wedge under the toes does the same with a perpendicular CR."}, {"q": "For a tangential projection of the sesamoids (Lewis method), the patient is:", "options": ["Prone, with the great toe dorsiflexed against the IR", "Supine, with the foot plantar-flexed", "Seated, with the foot flat on the IR", "Lateral, with the foot dorsiflexed"], "answer_index": 0, "explanation": "Dorsiflexing the great toe while prone lifts the sesamoids off the metatarsal head so a tangential CR shows them in profile."}, {"q": "On an AP projection of the great toe like this one, the paired ovoid bones over the head of the first metatarsal are the:", "options": ["Accessory navicular bones", "Os trigonum", "Sesamoids within the flexor hallucis brevis tendons", "Fabellae"], "answer_index": 2, "explanation": "Two sesamoids sit beneath the first metatarsal head; tangential views separate them from the metatarsal to check for fracture."}]}, {"modality": "Radiography", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Foot (AP axial, oblique, lateral, weight-bearing)", "image": {"file": "radiography__lower_extremity__foot.jpg", "caption": "Normal AP (dorsoplantar) right foot", "credit": "Mikael Häggström, M.D.", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_normal_right_foot_by_dorsoplantar_projection.jpg"}, "questions": [{"q": "For an AP foot like this one, the central ray is angled 10 degrees toward the:", "options": ["Heel", "Toes", "Medial malleolus", "Lateral malleolus"], "answer_index": 0, "explanation": "Angling 10 degrees posteriorly places the CR perpendicular to the metatarsals and opens the tarsometatarsal joints."}, {"q": "On an AP foot like this one, the heel (thicker tarsal area) is placed toward the:", "options": ["Anode end of the tube", "Center of the grid", "Cathode end of the tube", "Tube's filter side"], "answer_index": 2, "explanation": "The heel effect gives more intensity on the cathode side, helping penetrate the thicker tarsals while not overexposing the toes."}, {"q": "For AP weight-bearing feet, the CR is angled:", "options": ["10 degrees anteriorly, toward the toes", "15 degrees posteriorly, to the midpoint between the feet at the level of the metatarsal bases", "Perpendicular to each heel separately", "40 degrees cephalad to the long axis of the foot"], "answer_index": 1, "explanation": "The tube is angled 15 degrees toward the heels because the standing patient blocks a perpendicular beam to the metatarsals."}]}, {"modality": "Radiography", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Calcaneus (lateral, plantodorsal axial)", "image": {"file": "radiography__lower_extremity__calcaneus.jpg", "caption": "Lateral calcaneus/hindfoot radiograph", "credit": "Mikael Häggström", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:Calcaneal_fragment_-_lateral.jpg"}, "questions": [{"q": "For a plantodorsal axial calcaneus, the CR is angled about 40 degrees cephalad to the:", "options": ["Tibial plateau", "Plantar surface of the heel", "Long axis of the tibia", "Long axis of the foot"], "answer_index": 3, "explanation": "The 40-degree cephalad angle to the long axis of the foot projects the calcaneus without foreshortening."}, {"q": "During a plantodorsal axial calcaneus, the patient pulls the foot into dorsiflexion with a strap in order to:", "options": ["Show the subtalar joint in a lateral view", "Reduce motion of the toes", "Bring the plantar surface nearly perpendicular to the IR", "Open the ankle mortise"], "answer_index": 2, "explanation": "Dorsiflexion keeps the calcaneus aligned so the 40-degree cephalad CR projects it with little distortion."}, {"q": "Böhler's angle, measured on a lateral calcaneus, normally measures about:", "options": ["20-40 degrees", "0-10 degrees", "50-70 degrees", "90 degrees"], "answer_index": 0, "explanation": "A Böhler angle below about 20 degrees suggests a depressed calcaneal fracture involving the posterior facet."}]}, {"modality": "Radiography", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Ankle (AP, mortise, lateral, stress)", "image": {"file": "radiography__lower_extremity__ankle.jpg", "caption": "Normal ankle mortise view (15-degree internal rotation)", "credit": "Mikael Häggström", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_normal_ankle_-_15_degrees_internal_rotation.jpg"}, "questions": [{"q": "On a mortise view like this one, which line is placed parallel to the IR?", "options": ["The long axis of the foot", "The plantar surface of the heel", "A line through the first and fifth metatarsal heads", "The intermalleolar line"], "answer_index": 3, "explanation": "Rotating the leg until the intermalleolar line is parallel to the IR opens the mortise on both sides of the talus."}, {"q": "On a correctly positioned mortise view, the ankle joint space should appear:", "options": ["Open laterally but closed medially", "Open and uniform around the medial, superior, and lateral talus", "Closed, with the fibula over the talus", "Open only at the tibiotalar dome"], "answer_index": 1, "explanation": "An even joint space around the talus means the rotation was right; widening on one side suggests ligament injury."}, {"q": "For an AP ankle, the central ray is directed:", "options": ["To the medial malleolus", "Midway between the malleoli", "To the base of the fifth metatarsal", "3 inches above the lateral malleolus"], "answer_index": 1, "explanation": "Centering midway between the malleoli places the ankle joint in the center of the field for the AP."}]}, {"modality": "Radiography", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Tibia/fibula", "image": {"file": "radiography__lower_extremity__tibia-fibula.jpg", "caption": "AP and lateral tibia/fibula including the knee and ankle", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Medical_X-Ray_imaging_HAE04_nevit.jpg"}, "questions": [{"q": "For an AP tibia/fibula, the anode heel effect is best used by placing the:", "options": ["Ankle toward the cathode end", "Knee toward the anode end", "Leg perpendicular to the tube axis", "Knee toward the cathode end of the tube"], "answer_index": 3, "explanation": "The thicker proximal leg goes under the stronger cathode side so density is even from knee to ankle."}, {"q": "On a non-rotated AP tibia/fibula like this one, the fibula should:", "options": ["Slightly overlap the tibia at the proximal and distal tibiofibular joints", "Be completely free of the tibia along its length", "Be fully superimposed on the tibia", "Overlap the tibia only at the midshaft"], "answer_index": 0, "explanation": "Some overlap at both ends is normal; complete separation or heavy overlap means the leg was rotated."}, {"q": "For the lateral tibia/fibula, the patient lies on the affected side with the patella:", "options": ["Parallel to the IR", "Rotated 45 degrees medially", "Perpendicular to the IR", "Facing the IR"], "answer_index": 2, "explanation": "A patella perpendicular to the IR puts the leg in a true lateral, with the femoral condyles superimposed."}]}, {"modality": "Radiography", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Knee (AP, lateral, obliques, intercondylar fossa)", "image": {"file": "radiography__lower_extremity__knee.jpg", "caption": "Normal lateral knee", "credit": "Mikael Häggström, M.D.", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_a_normal_knee_by_lateral_projection.jpg"}, "questions": [{"q": "For a lateral knee like this one, the knee is flexed 20-30 degrees and the CR angled 5-7 degrees cephalad in order to:", "options": ["Superimpose the femoral condyles and avoid obscuring the joint space", "Show the tibial plateau on end", "Show the patella tangentially", "Open the intercondylar fossa"], "answer_index": 0, "explanation": "The slight cephalad angle compensates for the longer medial condyle so the condyles superimpose and the joint space is not obscured."}, {"q": "On a lateral knee like this one, flexion is limited to 20-30 degrees because more flexion:", "options": ["Superimposes the tibia over the femur", "Opens the knee joint too widely", "Pulls the patella into the intercondylar sulcus and can hide effusion or separate fracture fragments", "Forces the fibula behind the tibia"], "answer_index": 2, "explanation": "Greater flexion tightens the quadriceps tendon, drawing the patella into the sulcus and obscuring fat pad signs."}, {"q": "In the Holmblad method for the intercondylar fossa, the patient kneels with the knee flexed 60-70 degrees and the CR is:", "options": ["Angled 40 degrees caudad", "Perpendicular to the IR and the lower leg", "Angled 40 degrees cephalad", "Parallel to the femur"], "answer_index": 1, "explanation": "The kneeling patient leans forward 20-30 degrees from vertical, and a perpendicular CR passes through the open fossa."}]}, {"modality": "Radiography", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Patella (PA, Merchant, Settegast)", "image": {"file": "radiography__lower_extremity__patella.jpg", "caption": "Normal tangential (axial) patella projection", "credit": "Mikael Häggström, M.D.", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:X-ray_of_a_normal_patella.jpg"}, "questions": [{"q": "A PA patella is preferred over an AP patella because the PA:", "options": ["Shows the patellofemoral joint tangentially", "Allows the knee to be flexed 90 degrees", "Requires no grid", "Places the patella closer to the IR, giving sharper detail"], "answer_index": 3, "explanation": "Less OID means less magnification and blur; an AP may be used when the patient cannot lie prone."}, {"q": "For a PA patella, the leg is rotated about 5 degrees internally in order to:", "options": ["Show the proximal tibiofibular joint", "Open the intercondylar fossa", "Place the patella parallel to the IR", "Project the fibula free of the tibia"], "answer_index": 2, "explanation": "The patella normally faces slightly lateral; a little internal rotation centers it over the femur."}, {"q": "On a tangential patella image like this one, which can be assessed?", "options": ["The patellofemoral joint space and lateral subluxation of the patella", "The tibial plateau and tibial spines", "The proximal tibiofibular joint", "The femoral condyles in profile from the side"], "answer_index": 0, "explanation": "Tangential views show the patella sitting in the trochlear groove, so the joint space and any lateral tilt or subluxation are seen."}]}, {"modality": "Radiography", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Femur and long bone measurement", "image": {"file": "radiography__lower_extremity__femur.jpg", "caption": "Radiograph of the femur including the hip", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Medical_X-Ray_imaging_CYA03_nevit.jpg"}, "questions": [{"q": "For a mediolateral femur, the patient lies on the affected side with the unaffected leg:", "options": ["Placed over the affected leg", "Abducted 45 degrees", "Flexed to 90 degrees in front of the affected leg", "Placed behind the affected leg to prevent over-rotation"], "answer_index": 3, "explanation": "Bringing the unaffected leg behind keeps the pelvis from rolling and keeps the femur in a true lateral."}, {"q": "In a three-exposure orthoroentgenogram (scanogram) for leg length, which is correct?", "options": ["One long exposure is centered at the knee", "A radiopaque ruler lies beside the limbs, and the patient must not move between exposures at the hip, knee, and ankle", "The patient is turned lateral for the knee exposure", "No ruler is needed because the SID is fixed"], "answer_index": 1, "explanation": "Short exposures centered over each joint with a radiopaque ruler in place allow true length measurement; any movement makes it invalid."}, {"q": "If the lesser trochanter is prominent in profile on an AP proximal femur like this one, the leg was:", "options": ["Internally rotated 15-20 degrees", "Externally rotated", "In true anatomic position", "Abducted 45 degrees"], "answer_index": 1, "explanation": "External rotation turns the lesser trochanter medially into profile and foreshortens the femoral neck."}]}, {"modality": "CT", "region": "head", "region_label": "Head / Brain", "exam": "Noncontrast head (stroke, trauma)", "image": {"file": "ct__head__noncontrast-head-stroke-trauma.jpg", "caption": "Axial noncontrast head CT showing a hyperdense right middle cerebral artery (labelled) in acute ischemic stroke.", "credit": "Cerevisae", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Right_dense_MCA_sign_as_seen_on_CT_brain.jpg"}, "questions": [{"q": "This noncontrast head CT was obtained as the first step of an acute stroke protocol. The main reason the noncontrast scan comes first is to:", "options": ["Measure cerebral blood volume", "Exclude intracranial hemorrhage before thrombolytic therapy", "Demonstrate the circle of Willis", "Show the infarct core better than perfusion imaging"], "answer_index": 1, "explanation": "Thrombolysis is contraindicated when there is intracranial hemorrhage, so a fast noncontrast CT is done first to rule out blood before treatment decisions."}, {"q": "Which window setting is most typical for viewing brain parenchyma on noncontrast head CT, as in this image?", "options": ["WW 80 / WL 40", "WW 1500 / WL −600", "WW 2000 / WL 500", "WW 400 / WL 40"], "answer_index": 0, "explanation": "A narrow window around 80/40 maximizes gray–white matter contrast; 1500/−600 is a lung window and 2000/500 a bone window."}, {"q": "For a head CT ordered for trauma, which additional reconstruction is routinely created from the same raw data?", "options": ["A delayed post-contrast series", "A perfusion color map", "A 10 mm thick soft-tissue series only", "A high-spatial-frequency (bone) algorithm series to look for skull fractures"], "answer_index": 3, "explanation": "Raw data are reconstructed with a sharp bone kernel and viewed in a bone window so calvarial and skull base fractures are not missed."}]}, {"modality": "CT", "region": "head", "region_label": "Head / Brain", "exam": "CT perfusion and CTA head", "image": {"file": "ct__head__ct-perfusion-and-cta-head.jpg", "caption": "CT perfusion color maps (time-to-peak and cerebral blood volume) in a patient with an M1 middle cerebral artery occlusion.", "credit": "Shazia Mirza and Sankalp Gokhale", "license": "CC BY 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_perfusion_in_M1_artery_occlusion.png"}, "questions": [{"q": "To calculate perfusion maps like these, the software needs an arterial input function and a venous output function. The venous ROI is usually placed in the:", "options": ["Internal carotid artery", "Basilar artery", "Lateral ventricle", "Superior sagittal sinus"], "answer_index": 3, "explanation": "A large dural venous sinus, usually the superior sagittal sinus, gives the venous output curve; the arterial input is taken from a major artery such as the ACA or MCA."}, {"q": "A brain CT perfusion study usually uses a small, tight contrast bolus injected at about:", "options": ["0.5–1 mL/s", "1.5–2 mL/s", "10–12 mL/s", "4–6 mL/s"], "answer_index": 3, "explanation": "A fast injection of roughly 35–50 mL at 4–6 mL/s gives the sharp first-pass enhancement curve that perfusion calculations depend on."}, {"q": "A patient with suspected large-vessel stroke has no known history of kidney disease. Regarding CTA and CT perfusion, current stroke guidance supports:", "options": ["Waiting for a serum creatinine result before any contrast", "Using noncontrast imaging only", "Proceeding with CTA without waiting for a creatinine result", "Giving oral contrast instead of IV contrast"], "answer_index": 2, "explanation": "Because treatment is time-critical, CTA can proceed before a creatinine result in patients without a history of renal impairment; the delay outweighs the small risk."}]}, {"modality": "CT", "region": "head", "region_label": "Head / Brain", "exam": "Sinuses", "image": {"file": "ct__head__sinuses.jpg", "caption": "Coronal CT of the paranasal sinuses through the ostiomeatal complex, bone window.", "credit": "Mikael Häggström (from Paşaoğlu L et al.)", "license": "CC BY 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_of_the_ostiomeatal_complex,_coronal_plane,_no_annotations.png"}, "questions": [{"q": "This coronal image shows the ostiomeatal complex. It drains the maxillary, frontal and anterior ethmoid sinuses into the:", "options": ["Middle meatus", "Inferior meatus", "Sphenoethmoidal recess", "Superior meatus"], "answer_index": 0, "explanation": "The maxillary ostium, infundibulum and hiatus semilunaris empty into the middle meatus, so blockage here can obstruct several sinuses at once."}, {"q": "Sinus CT for chronic sinusitis can often use a low mAs technique mainly because:", "options": ["IV contrast is always given", "The sinuses are not radiosensitive", "Air and bone give high inherent contrast in the sinuses", "Thick slices are used"], "answer_index": 2, "explanation": "The large difference in attenuation between air, mucosa and bone keeps the anatomy visible even at low dose, which also limits lens dose."}, {"q": "When direct coronal sinus images were acquired (before routine MPR), the patient was usually positioned:", "options": ["Prone with the chin hyperextended", "Supine with the head flexed", "Lateral decubitus", "Upright seated"], "answer_index": 0, "explanation": "Prone with the neck extended places the coronal plane in the gantry and lets fluid fall away from the ostiomeatal complex; today coronal images are usually reformatted from thin axial data."}]}, {"modality": "CT", "region": "head", "region_label": "Head / Brain", "exam": "Temporal bones / IAC", "image": {"file": "ct__head__temporal-bones-iac.jpg", "caption": "Axial high-resolution CT of the temporal bones at the skull base, bone window.", "credit": "Hellerhoff", "license": "CC BY 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT-Felsenbein-15.jpg"}, "questions": [{"q": "On this axial temporal bone CT, the air-filled honeycomb spaces behind the external auditory canal on each side are the:", "options": ["Mastoid air cells", "Ethmoid air cells", "Sphenoid sinus", "Jugular foramina"], "answer_index": 0, "explanation": "The mastoid process of the temporal bone contains air cells that connect with the middle ear through the mastoid antrum."}, {"q": "Temporal bone images are usually reconstructed separately for each side with a small display FOV (about 9–10 cm) mainly to:", "options": ["Reduce pixel size and improve spatial resolution", "Lower the patient dose", "Reduce scan time", "Improve low-contrast detectability of the brain"], "answer_index": 0, "explanation": "A smaller DFOV with the same matrix gives smaller pixels, which helps show tiny structures such as the ossicles and cochlea."}, {"q": "Which cranial nerves pass through the internal auditory canal?", "options": ["Facial (VII) and vestibulocochlear (VIII)", "Trigeminal (V) and abducens (VI)", "Glossopharyngeal (IX) and vagus (X)", "Optic (II) and oculomotor (III)"], "answer_index": 0, "explanation": "The IAC carries cranial nerves VII and VIII, so widening or erosion of the canal can signal a vestibular schwannoma."}]}, {"modality": "CT", "region": "head", "region_label": "Head / Brain", "exam": "Orbits", "image": {"file": "ct__head__orbits.jpg", "caption": "Axial CT of the orbits showing small bilateral calcified optic disc drusen at the optic nerve heads.", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Optic_disc_drusen_73jw_-_CT_axial_-_001.jpg"}, "questions": [{"q": "On this axial orbit CT of a 73-year-old, the tiny bright foci where each optic nerve meets the back of the globe are most consistent with:", "options": ["Optic disc drusen", "Intraocular air", "The crystalline lens", "Retrobulbar hemorrhage"], "answer_index": 0, "explanation": "Optic disc drusen are calcified deposits at the optic nerve head and appear as punctate hyperdensities on CT."}, {"q": "To show the whole length of the optic nerve on one axial orbit image, the axial plane is aligned:", "options": ["Perpendicular to the hard palate", "Parallel to the vertex", "Parallel to the mandible", "Along the course of the optic nerve (neuro-ocular plane)"], "answer_index": 3, "explanation": "Angling the axial plane along the optic nerve (from the lens through the optic canal) shows the globe, nerve and orbital apex in one slice."}, {"q": "In thyroid eye disease (Graves ophthalmopathy), which extraocular muscle is most often enlarged on orbit CT?", "options": ["Lateral rectus", "Superior oblique", "Inferior rectus", "Levator palpebrae"], "answer_index": 2, "explanation": "The inferior rectus is most often involved, followed by the medial and superior recti; the muscle bellies enlarge while the tendons are spared."}]}, {"modality": "CT", "region": "head", "region_label": "Head / Brain", "exam": "Maxillofacial and mandible", "image": {"file": "ct__head__maxillofacial-and-mandible.jpg", "caption": "3D volume-rendered CT of the facial skeleton showing a displaced mandible fracture (arrows).", "credit": "Coronation Dental Specialty Group", "license": "CC BY 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:3D_CT_mandible_fracture.jpg"}, "questions": [{"q": "This 3D volume-rendered image is reconstructed from thin axial facial CT data. Compared with the source images, its main value is to:", "options": ["Replace review of the axial and MPR images", "Lower the radiation dose", "Improve soft-tissue contrast", "Show fragment displacement and spatial relationships for surgical planning"], "answer_index": 3, "explanation": "Volume rendering gives a clear overview of displacement, but subtle nondisplaced fractures can be hidden, so the source and MPR images must still be reviewed."}, {"q": "Because the mandible acts as a ring, a fracture seen at one site should prompt a search for a second fracture, most often at the:", "options": ["Contralateral angle or condyle", "Hyoid bone", "Nasal bones", "Zygomatic arch on the same side"], "answer_index": 0, "explanation": "Mandible fractures are frequently multiple; a parasymphyseal fracture is commonly paired with a contralateral angle or condylar fracture."}, {"q": "A routine CT for suspected facial fractures is usually performed:", "options": ["Without IV contrast, using thin bone-algorithm slices with MPRs", "With IV contrast in the arterial phase", "With oral contrast", "With 10 mm slices only"], "answer_index": 0, "explanation": "Fracture detection depends on spatial resolution, so thin noncontrast slices reconstructed with a bone kernel and reformatted in coronal and sagittal planes are standard."}]}, {"modality": "CT", "region": "head", "region_label": "Head / Brain", "exam": "TMJs", "image": {"file": "ct__head__tmjs.jpg", "caption": "Axial bone-window CT at the skull base in bilateral temporomandibular joint dislocation (empty mandibular fossae).", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Kiefersperre_bei_beidseitiger_Kiefergelenksluxation_93W_-_CT_axial_-_001.jpg"}, "questions": [{"q": "On this axial CT of a patient who cannot close her mouth, both mandibular (glenoid) fossae are empty. This indicates:", "options": ["Bilateral condylar agenesis", "Normal closed-mouth anatomy", "Bilateral anterior TMJ dislocation", "Bilateral mastoiditis"], "answer_index": 2, "explanation": "In anterior dislocation the mandibular condyles move forward past the articular eminence and lock there, leaving the fossae empty."}, {"q": "Compared with MRI, CT of the temporomandibular joints is best for evaluating:", "options": ["Articular disc position", "Osseous changes such as erosions, ankylosis or fracture", "Joint effusion", "Bone marrow edema"], "answer_index": 1, "explanation": "CT shows cortical bone detail well, while MRI is the study of choice for the articular disc and soft tissues."}, {"q": "TMJ CT reformats are usually displayed in oblique planes set relative to the:", "options": ["Hard palate", "Long axis of each mandibular condyle", "Orbitomeatal line", "Cervical spine"], "answer_index": 1, "explanation": "Oblique sagittal and coronal reformats aligned to each condyle's long axis show the condyle, fossa and eminence without distortion."}]}, {"modality": "CT", "region": "neck", "region_label": "Neck / Larynx / Airway", "exam": "Soft-tissue neck with IV contrast", "image": {"file": "ct__neck__soft-tissue-neck-with-iv-contrast.jpg", "caption": "Contrast-enhanced axial neck CT showing a large retropharyngeal abscess.", "credit": "James Heilman, MD", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:LargeRetroAbsTra.png"}, "questions": [{"q": "A routine contrast-enhanced soft-tissue neck CT typically covers from the:", "options": ["Vertex to the hyoid bone", "Hyoid bone to the diaphragm", "Skull base to the aortic arch", "Sella to the carina only"], "answer_index": 2, "explanation": "Coverage from the skull base to the aortic arch includes the entire upper aerodigestive tract and the cervical lymph node chains."}, {"q": "The collection on this contrast-enhanced image lies behind the pharynx, in the retropharyngeal space. Infection here is dangerous because it can spread down into the:", "options": ["Orbit", "Posterior mediastinum", "Maxillary sinus", "Subarachnoid space of the brain"], "answer_index": 1, "explanation": "The retropharyngeal and danger spaces run from the skull base into the mediastinum, so deep neck infection can track down and cause mediastinitis."}, {"q": "For a soft-tissue neck CT, a delay of roughly 60–90 seconds (or a split bolus) is used instead of an early arterial scan mainly to:", "options": ["Lower the contrast dose to zero", "Image the circle of Willis", "Reduce swallowing motion", "Let mucosa, lymph nodes and lesion rims enhance while vessels are still opacified"], "answer_index": 3, "explanation": "Later timing allows tissue and nodal enhancement; a split bolus can give both soft-tissue enhancement and vascular opacification in one acquisition."}]}, {"modality": "CT", "region": "neck", "region_label": "Neck / Larynx / Airway", "exam": "Larynx / airway", "image": {"file": "ct__neck__larynx-airway.jpg", "caption": "CT virtual endoscopic (endoluminal volume-rendered) view of the trachea in a patient with tracheobronchial papillomatosis (arrow).", "credit": "Nootherone321", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_tracheal_papillomatosis_volume.png"}, "questions": [{"q": "This image is a CT virtual endoscopy of the airway. Compared with fiberoptic bronchoscopy, its main limitation is that it:", "options": ["Cannot show the airway beyond a tight stenosis", "Cannot assess mucosal color or obtain tissue for biopsy", "Requires general anesthesia", "Needs IV contrast"], "answer_index": 1, "explanation": "Virtual endoscopy can look past a narrowing that a scope cannot cross, but it shows only surface shape: no mucosal color, and no biopsy."}, {"q": "To evaluate true vocal cord motion during a larynx CT, the patient can be asked to:", "options": ["Take a deep breath and hold it", "Swallow repeatedly", "Phonate a prolonged \"eee\" during scanning", "Perform a forceful cough"], "answer_index": 2, "explanation": "Phonation brings the vocal cords together so cord motion and symmetry can be assessed; quiet breathing shows them abducted."}, {"q": "Axial images for a larynx CT are usually reconstructed parallel to the:", "options": ["Hard palate", "Plane of the true vocal cords", "Clivus", "Mandibular body"], "answer_index": 1, "explanation": "Aligning slices to the true cords allows symmetric comparison of both sides and accurate assessment of tumor spread above and below the glottis."}]}, {"modality": "CT", "region": "neck", "region_label": "Neck / Larynx / Airway", "exam": "CTA neck (carotid and vertebral)", "image": {"file": "ct__neck__cta-neck-carotid-and-vertebral.jpg", "caption": "Axial CT angiogram of the neck showing a roughly 70% stenosis of the right internal carotid artery (arrow).", "credit": "James Heilman, MD", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:70PerBlockedRtCarotidACT.png"}, "questions": [{"q": "The arrow shows a narrowed right internal carotid lumen. In the NASCET method, the narrowest residual lumen is compared with the diameter of the:", "options": ["Common carotid artery", "Normal ICA distal to the stenosis", "Carotid bulb", "Contralateral vertebral artery"], "answer_index": 1, "explanation": "NASCET percent stenosis = (1 − narrowest lumen / normal distal ICA diameter) × 100."}, {"q": "Scan coverage for a CTA of the neck usually extends from the:", "options": ["Hyoid bone to the skull base", "Carina to the diaphragm", "Aortic arch through the circle of Willis", "C1 to C7 only"], "answer_index": 2, "explanation": "Including the aortic arch shows the origins of the great vessels, and extending above the skull base shows the intracranial carotid and vertebrobasilar circulation."}, {"q": "On a neck CTA, the vertebral artery usually enters the cervical transverse foramina at the level of:", "options": ["C1", "C6", "C3", "T2"], "answer_index": 1, "explanation": "Each vertebral artery typically enters the transverse foramen of C6 and ascends through C6–C1 before passing through the foramen magnum."}]}, {"modality": "CT", "region": "chest", "region_label": "Chest / Thorax / Heart", "exam": "Routine chest with or without contrast", "image": {"file": "ct__chest__routine-chest-with-or-without-contrast.jpg", "caption": "Contrast-enhanced axial chest CT in a soft-tissue window showing right-sided pneumonia (circled).", "credit": "James Heilman, MD", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_scan_of_the_chest,_demonstrating_right-sided_pneumonia.jpg"}, "questions": [{"q": "The circled area on this chest CT is airless lung tissue that still contains visible bronchi. This finding is best described as:", "options": ["Pneumothorax", "Emphysema", "Consolidation", "Pneumomediastinum"], "answer_index": 2, "explanation": "Consolidation means alveolar air has been replaced by fluid, pus or cells; air bronchograms within it are typical of pneumonia."}, {"q": "A routine chest CT is acquired at suspended full inspiration mainly to:", "options": ["Reduce the contrast dose", "Expand the lungs and reduce dependent atelectasis that can mimic disease", "Raise the heart rate", "Move the diaphragm into the scan range"], "answer_index": 1, "explanation": "Full inspiration aerates the lungs and spreads out the vessels, so small nodules and true disease are easier to separate from collapsed lung."}, {"q": "In a routine chest CT, IV contrast is particularly helpful for:", "options": ["Detecting calcified granulomas", "Measuring emphysema", "Showing honeycombing", "Telling hilar vessels apart from lymph nodes or masses"], "answer_index": 3, "explanation": "Enhanced vessels can be distinguished from soft-tissue nodes and masses in the hila and mediastinum; calcification and lung parenchyma do not require contrast."}]}, {"modality": "CT", "region": "chest", "region_label": "Chest / Thorax / Heart", "exam": "CT pulmonary angiography", "image": {"file": "ct__chest__ct-pulmonary-angiography.jpg", "caption": "Axial CT pulmonary angiogram showing a saddle embolus with occlusion of the left pulmonary artery.", "credit": "Rvahudson", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:CTA_Chest_With_Massive_Pulmonary_Embolism_and_Complete_Occlusion.jpg"}, "questions": [{"q": "On this CT pulmonary angiogram, a filling defect straddles the bifurcation of the main pulmonary artery. This is called a:", "options": ["Hampton hump", "Mosaic perfusion", "Westermark sign", "Saddle embolus"], "answer_index": 3, "explanation": "A saddle embolus lodges at the main pulmonary artery bifurcation and extends into both main branches; Hampton hump and Westermark are radiographic signs."}, {"q": "For a CT pulmonary angiogram using bolus tracking, the monitoring ROI is usually placed in the:", "options": ["Descending aorta", "Main pulmonary artery", "Left atrium", "Superior vena cava"], "answer_index": 1, "explanation": "Triggering from the main pulmonary artery times the scan to peak pulmonary arterial enhancement."}, {"q": "Why are patients coached to avoid a forceful Valsalva maneuver during CT pulmonary angiography?", "options": ["It can draw unopacified IVC blood into the right heart, causing a transient contrast interruption", "It increases the radiation dose", "It causes beam-hardening artifact in the lungs", "It slows the gantry rotation"], "answer_index": 0, "explanation": "Deep inspiration with straining increases inflow of unenhanced IVC blood, diluting pulmonary arterial contrast and mimicking or hiding emboli."}]}, {"modality": "CT", "region": "chest", "region_label": "Chest / Thorax / Heart", "exam": "Aortic dissection CTA", "image": {"file": "ct__chest__aortic-dissection-cta.jpg", "caption": "Contrast-enhanced axial chest CT showing an intimal flap in the ascending aorta (arrow), a Stanford type A dissection.", "credit": "James Heilman, MD", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:DissectionCT.png"}, "questions": [{"q": "The intimal flap on this image separates the true and false lumens. Which feature usually identifies the false lumen?", "options": ["It is smaller and enhances first", "It is larger, may enhance later, and can show a “beak” sign or cobwebs", "It is always completely clotted", "It contains the coronary artery origins"], "answer_index": 1, "explanation": "The false lumen is usually larger with slower flow, and shows an acute angle (beak sign) and thin strands (cobwebs) at the flap."}, {"q": "In suspected acute aortic syndrome, a noncontrast series is often obtained before the CTA mainly to detect:", "options": ["Intramural hematoma as a high-attenuation crescent in the aortic wall", "Pulmonary embolism", "Coronary stenosis", "Contrast extravasation"], "answer_index": 0, "explanation": "Acute intramural hematoma appears as a hyperdense crescent on noncontrast images and can be hidden once the lumen is filled with contrast."}, {"q": "Coverage for an aortic dissection CTA usually extends from above the aortic arch to the:", "options": ["Diaphragm", "Renal arteries", "Carina", "Iliac and common femoral arteries"], "answer_index": 3, "explanation": "Scanning through the pelvis shows the full extent of the flap, involvement of branch vessels and the iliac and femoral access vessels for repair."}]}, {"modality": "CT", "region": "chest", "region_label": "Chest / Thorax / Heart", "exam": "HRCT", "image": {"file": "ct__chest__hrct.jpg", "caption": "High-resolution chest CT (lung window) in usual interstitial pneumonia showing basal subpleural reticulation and honeycombing.", "credit": "Yale Rosen", "license": "CC BY-SA 2.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_scan_in_usual_interstitial_pneumonia_(UIP).jpg"}, "questions": [{"q": "This HRCT shows clustered, thick-walled cystic airspaces stacked in rows along the pleura. This appearance is called:", "options": ["Honeycombing", "Ground-glass opacity", "Tree-in-bud", "Centrilobular emphysema"], "answer_index": 0, "explanation": "Honeycombing means stacked subpleural cysts from end-stage fibrosis and is a key feature of the UIP pattern."}, {"q": "HRCT images are reconstructed with:", "options": ["Thick (5–10 mm) sections and a soft-tissue kernel", "Thin sections and a smooth kernel only", "Thin (about 1–1.5 mm) sections and a high-spatial-frequency (sharp) kernel", "Any slice thickness, since only the window matters"], "answer_index": 2, "explanation": "Thin sections and a sharp algorithm bring out the fine interstitial detail of secondary pulmonary lobules."}, {"q": "In the usual interstitial pneumonia (UIP) pattern shown here, fibrosis is typically most severe in the:", "options": ["Upper lobes, around the bronchovascular bundles", "Subpleural lung bases", "Central perihilar lung", "Lung apices only"], "answer_index": 1, "explanation": "UIP has a basal and subpleural predominance, which is why posterior bases need careful review."}]}, {"modality": "CT", "region": "chest", "region_label": "Chest / Thorax / Heart", "exam": "Low-dose lung screening", "image": {"file": "ct__chest__low-dose-lung-screening.jpg", "caption": "Axial low-dose chest CT (1.25 mm, lung kernel, 120 kV) showing a small calcified nodule in the left upper lobe (circled).", "credit": "Ptrump16", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT-Low-Dose-1.25-Lung-Calcified-Nodule.jpg"}, "questions": [{"q": "The circled nodule on this screening CT is completely calcified. Under Lung-RADS, a nodule with a benign calcification pattern is placed in category:", "options": ["1 (negative)", "3 (probably benign)", "4A (suspicious)", "4X (very suspicious)"], "answer_index": 0, "explanation": "Nodules with benign features such as complete, central, popcorn or laminated calcification are Lung-RADS category 1, so routine annual screening continues."}, {"q": "This screening scan was reconstructed at 1.25 mm. Thin sections are used mainly to:", "options": ["Shorten the scan time", "Increase dose to improve contrast", "Accurately characterize and measure small nodules", "Allow contrast timing"], "answer_index": 2, "explanation": "Thin slices reduce partial-volume averaging, so small nodules can be measured, compared over time and checked for calcification or fat."}, {"q": "How is the scan in this screening program typically acquired?", "options": ["With IV contrast in the arterial phase", "With prone and supine contrast-enhanced scans", "With ECG gating", "Without IV contrast, in one breath-hold at full inspiration"], "answer_index": 3, "explanation": "Screening needs no contrast; a single breath-hold at full inspiration through the whole lung keeps dose low while showing nodules."}]}, {"modality": "CT", "region": "chest", "region_label": "Chest / Thorax / Heart", "exam": "Coronary CTA and calcium scoring", "image": {"file": "ct__chest__coronary-cta-and-calcium-scoring.jpg", "caption": "Coronary artery calcium scoring analysis (130 HU threshold) showing LAD calcification with a total Agatston score of 213.", "credit": "MBq", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:CCTA_Agatston-Score.png"}, "questions": [{"q": "This analysis uses a 130 HU threshold. In the Agatston method, each calcified lesion's area is multiplied by a weighting factor based on its:", "options": ["Distance from the coronary ostium", "Heart rate at acquisition", "Peak attenuation (density)", "Patient age"], "answer_index": 2, "explanation": "Weighting factors from 1 to 4 correspond to peak densities of 130–199, 200–299, 300–399 and ≥400 HU."}, {"q": "The total Agatston score on this report is 213. Using common categories, this represents:", "options": ["No identifiable plaque", "Minimal plaque", "Moderate plaque burden", "Severe plaque burden"], "answer_index": 2, "explanation": "Common cutoffs are 0 none, 1–10 minimal, 11–100 mild, 101–400 moderate and over 400 severe."}, {"q": "What is the purpose of giving a nitrate under the tongue immediately before contrast-enhanced coronary imaging?", "options": ["Slow the heart rate", "Prevent contrast reactions", "Dilate the coronary arteries for better lumen visualization", "Lower the radiation dose"], "answer_index": 2, "explanation": "Nitroglycerin dilates the epicardial coronaries, which improves visibility of small segments; heart rate control comes from beta-blockers."}]}, {"modality": "CT", "region": "chest", "region_label": "Chest / Thorax / Heart", "exam": "TAVR planning", "image": {"file": "ct__chest__tavr-planning.jpg", "caption": "Coronal CT showing the stent frame of a transcatheter aortic valve (valve-in-valve) at the aortic root; cropped from a radiograph and CT composite.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:TAVI_in_biologischem_Aortenklappenersatz_bei_Restenose_82W_-_CR_schraeg_und_CT_coronar_-_001.jpg"}, "questions": [{"q": "Where is the valve-sizing measurement taken on the double-oblique reconstruction of the aortic root?", "options": ["Sinotubular junction", "Virtual basal ring through the lowest hinge points of the three cusps", "Mid-ascending aorta at the pulmonary artery level", "Left ventricular outflow tract 2 cm below the valve"], "answer_index": 1, "explanation": "The annulus is a virtual ring defined by the nadirs of the three cusps; its area and perimeter guide prosthesis size."}, {"q": "A TAVR planning CT usually adds a CTA of the abdominal aorta, iliac and femoral arteries mainly to evaluate:", "options": ["Renal function", "Liver lesions", "Access-vessel diameter, calcification and tortuosity for transfemoral delivery", "Bone density"], "answer_index": 2, "explanation": "The delivery sheath is usually passed through the femoral and iliac arteries, so their size, calcium and tortuosity decide whether transfemoral access is safe."}, {"q": "This image shows a transcatheter valve stent frame after implantation. Which pre-procedure CT measurement helps predict the risk of coronary obstruction?", "options": ["Thickness of the sternum", "Pulmonary artery diameter", "Height of the coronary ostia above the annulus", "Size of the left atrial appendage"], "answer_index": 2, "explanation": "A low coronary ostial height (with narrow sinuses) increases the risk that the displaced native leaflets block a coronary origin."}]}, {"modality": "CT", "region": "abdomen", "region_label": "Abdomen", "exam": "Routine abdomen/pelvis (portal venous)", "image": {"file": "ct__abdomen__routine-abdomen-pelvis-portal-venous.jpg", "caption": "Coronal reformation from a routine contrast-enhanced abdomen/pelvis CT (portal venous phase, 3 mm) with axial reference image; normal anatomy.", "credit": "Mikael Häggström, M.D.", "license": "CC0 1.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_of_a_normal_abdomen_and_pelvis,_coronal_plane_92.png"}, "questions": [{"q": "This coronal image was reformatted from the axial data of a routine abdomen/pelvis CT. Which reconstruction gives the best-quality coronal and sagittal reformations?", "options": ["Thin, overlapping axial sections approaching isotropic voxels", "Thick (8–10 mm) contiguous axial sections", "A sharp lung kernel at a larger display field of view", "Axial sections reconstructed with a 50% gap between slices"], "answer_index": 0, "explanation": "MPR quality depends on thin source images with overlap so voxels are nearly isotropic; thick or gapped slices produce stair-step, blurred reformats."}, {"q": "The standard scan range for a routine adult abdomen/pelvis CT is:", "options": ["From the xiphoid process to the iliac crests", "From just above the diaphragmatic domes through the pubic symphysis", "From the lung apices to the ischial tuberosities", "From T12 to the lesser trochanters"], "answer_index": 1, "explanation": "Coverage must include the entire liver dome superiorly and the bladder and pubic symphysis inferiorly."}, {"q": "When positive oral contrast is used for a routine abdomen/pelvis CT, it is usually started about 60–90 minutes before scanning chiefly to:", "options": ["Increase hepatic parenchymal enhancement", "Lower the volume of IV contrast needed", "Opacify distal small bowel and colon so unopacified loops are not mistaken for masses or fluid collections", "Reduce the effective radiation dose"], "answer_index": 2, "explanation": "Adequate transit time lets contrast reach distal bowel; unopacified loops can mimic abscesses, nodes or masses."}]}, {"modality": "CT", "region": "abdomen", "region_label": "Abdomen", "exam": "Multiphase liver", "image": {"file": "ct__abdomen__multiphase-liver.jpg", "caption": "Late arterial (left) and portal venous (right) phase CT in a cirrhotic liver with hepatocellular carcinoma.", "credit": "Kristie Guite, Louis Hinshaw and Fred Lee", "license": "CC BY 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Arterial_and_portal_venous_phase_CT_of_cirrhosis_and_hepatocellular_carcinoma.jpg"}, "questions": [{"q": "In this arterial/portal venous pair, a hepatocellular carcinoma that is hyperenhancing in the arterial phase and becomes darker than the surrounding liver on the portal venous or delayed phase is showing:", "options": ["Centripetal fill-in", "Capsular retraction", "Partial-volume averaging", "Washout"], "answer_index": 3, "explanation": "Arterial hyperenhancement followed by \"washout\" (relative hypoattenuation) on later phases is the hallmark CT pattern of HCC in a cirrhotic liver."}, {"q": "For a multiphase liver CT, the late hepatic arterial phase is typically acquired at approximately:", "options": ["70–80 seconds after the start of injection", "10–15 seconds after the start of injection", "35–40 seconds after the start of injection", "3–5 minutes after the start of injection"], "answer_index": 2, "explanation": "Late arterial imaging (~35–40 s, or ~15–20 s after a bolus-tracking trigger in the aorta) maximizes conspicuity of hypervascular lesions."}, {"q": "On a multiphase liver CT, which lesion characteristically shows progressive enhancement that is most evident on delayed (about 3–5 minute) images because of its fibrous stroma?", "options": ["Intrahepatic cholangiocarcinoma", "Simple hepatic cyst", "Hepatocellular carcinoma", "Focal fatty infiltration"], "answer_index": 0, "explanation": "Fibrous tumors such as intrahepatic cholangiocarcinoma retain contrast and enhance progressively, so a delayed phase helps characterize them."}]}, {"modality": "CT", "region": "abdomen", "region_label": "Abdomen", "exam": "Multiphase pancreas", "image": {"file": "ct__abdomen__multiphase-pancreas.jpg", "caption": "Pancreatic protocol CT: non-contrast, early arterial and late arterial (pancreatic parenchymal) phases showing a hypoenhancing pancreatic mass (arrows).", "credit": "Kristie Guite, Louis Hinshaw and Fred Lee", "license": "CC BY 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Non-contrast,_early_arterial,_and_late_arterial_phase_CT_of_pancreas_with_hypoenhancing_mass.jpg"}, "questions": [{"q": "When staging pancreatic adenocarcinoma on a pancreatic protocol CT, tumor encasement (more than 180° contact) of which vessel generally makes the tumor unresectable?", "options": ["Gastroduodenal artery", "Splenic vein", "Inferior mesenteric vein", "Superior mesenteric artery"], "answer_index": 3, "explanation": "Encasement of the SMA, celiac axis or common hepatic artery usually defines locally advanced, unresectable disease."}, {"q": "A pancreatic mass that is hypoenhancing relative to normal pancreas on the pancreatic phase is most typical of:", "options": ["Insulinoma", "Ductal adenocarcinoma", "Serous cystadenoma", "Pancreatic lipoma"], "answer_index": 1, "explanation": "Ductal adenocarcinoma is hypovascular and desmoplastic; neuroendocrine tumors such as insulinoma are usually hyperenhancing."}, {"q": "For a pancreatic protocol CT, which oral contrast is generally preferred?", "options": ["Neutral oral contrast such as water", "Dilute positive barium for maximum bowel opacification", "No fluid at all for 12 hours", "Positive iodinated contrast given 2 hours before"], "answer_index": 0, "explanation": "Water distends the duodenum without obscuring the ampulla and duodenal wall or interfering with vascular 3D reconstructions."}]}, {"modality": "CT", "region": "abdomen", "region_label": "Abdomen", "exam": "Adrenal protocol", "image": {"file": "ct__abdomen__adrenal-protocol.jpg", "caption": "Unenhanced axial CT showing a well-defined, low-attenuation right adrenal adenoma (arrow).", "credit": "Antonino Guerrisi, Daniele Marin, Mahbubeh Baski, Pietro Guerrisi, Federica Capozza, and Carlo Catalano", "license": "CC BY 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_of_adrenal_adenoma.jpg"}, "questions": [{"q": "On this unenhanced adrenal image, the region of interest used to measure the nodule’s attenuation should cover roughly one-half to two-thirds of the lesion and avoid its edges in order to:", "options": ["Increase the measured CT number", "Avoid partial-volume averaging with surrounding fat and include representative tissue", "Reduce image noise to zero", "Measure the adjacent kidney at the same time"], "answer_index": 1, "explanation": "An ROI that touches the lesion margin averages in surrounding fat or tissue and gives a falsely low or high HU value."}, {"q": "In an adrenal washout protocol, the delayed acquisition is typically obtained how long after contrast injection?", "options": ["45 minutes", "2 minutes", "15 minutes", "2 hours"], "answer_index": 2, "explanation": "The standard adrenal protocol includes unenhanced, portal venous (~60–75 s) and 15-minute delayed images to calculate washout."}, {"q": "RELATIVE percentage washout of an adrenal nodule is calculated using which two acquisitions?", "options": ["Unenhanced and 15-minute delayed", "Arterial and portal venous", "Unenhanced and portal venous", "Portal venous (enhanced) and 15-minute delayed"], "answer_index": 3, "explanation": "Relative washout = (enhanced − delayed)/enhanced × 100, so it can be used when no unenhanced scan was obtained; ≥40% favors adenoma."}]}, {"modality": "CT", "region": "abdomen", "region_label": "Abdomen", "exam": "Multiphase kidneys / CT urogram", "image": {"file": "ct__abdomen__multiphase-kidneys-ct-urogram.jpg", "caption": "Coronal non-contrast CT (left) and excretory-phase CT urography (right): opacified collecting system shows the renal-sinus fluid to be parapelvic cysts.", "credit": "Mikael Häggström, M.D.", "license": "CC0 1.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_of_peripelvic_cysts_with_non-contrast_and_urography.jpg"}, "questions": [{"q": "In this case, the excretory-phase images on the right fill the collecting system with contrast. The excretory phase is typically acquired about:", "options": ["25–35 seconds after injection", "70–90 seconds after injection", "8–15 minutes after injection", "60 minutes after injection"], "answer_index": 2, "explanation": "Excretory (pyelographic) images are obtained several minutes after injection, commonly 8–15 min, once contrast fills the calyces, pelves and ureters."}, {"q": "In CT urography, IV saline hydration or low-dose furosemide is sometimes given before the excretory phase mainly to:", "options": ["Improve ureteral distension and opacification while diluting very dense excreted contrast", "Speed contrast clearance from the liver", "Prevent the need for an unenhanced scan", "Increase renal cortical enhancement in the arterial phase"], "answer_index": 0, "explanation": "Better urine flow distends and fills the ureters more completely and reduces streak artifact from overly concentrated contrast."}, {"q": "On a renal mass protocol, an increase in attenuation greater than about how many HU from unenhanced to enhanced images indicates true enhancement of a lesion?", "options": ["5 HU", "150 HU", "60 HU", "20 HU"], "answer_index": 3, "explanation": "Enhancement of more than ~20 HU indicates a solid or enhancing component; 10–20 HU is equivocal and may reflect pseudoenhancement."}]}, {"modality": "CT", "region": "abdomen", "region_label": "Abdomen", "exam": "Renal stone", "image": {"file": "ct__abdomen__renal-stone.jpg", "caption": "Noncontrast axial CT showing a dense mid-ureteral calculus (arrow) with associated hydronephrosis.", "credit": "James Heilman, MD", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Midureterstonehydro.png"}, "questions": [{"q": "On this noncontrast image, the arrow marks a dense focus along the course of the ureter. Which sign favors a ureteral stone rather than a pelvic phlebolith?", "options": ["Comet-tail sign", "Soft-tissue rim sign", "Central lucency within the calcification", "Location below the ischial spines"], "answer_index": 1, "explanation": "A rim of edematous ureteral wall around the calcification (rim sign) indicates a ureteral stone; the comet-tail sign and central lucency favor a phlebolith."}, {"q": "Why can a renal stone CT usually be performed with a markedly reduced radiation dose compared with a routine abdomen CT?", "options": ["Stones are very high in contrast relative to surrounding tissue, so more image noise is acceptable", "Stones absorb less radiation than soft tissue", "Only the kidneys are scanned", "Noncontrast scans always need less mAs regardless of the task"], "answer_index": 0, "explanation": "The large attenuation difference between calculi and soft tissue lets stones be detected even in noisy low-dose images."}, {"q": "In a renal stone CT, the patient is sometimes rescanned prone over the bladder base. The purpose is to:", "options": ["Lower the radiation dose of the main scan", "Distinguish a stone impacted at the ureterovesical junction from one already passed into the bladder", "Improve renal parenchymal enhancement", "Eliminate respiratory motion artifact"], "answer_index": 1, "explanation": "A stone that has passed into the bladder falls to the dependent wall when the patient is prone, whereas an impacted UVJ stone stays fixed."}]}, {"modality": "CT", "region": "abdomen", "region_label": "Abdomen", "exam": "CT enterography and appendicitis", "image": {"file": "ct__abdomen__ct-enterography-and-appendicitis.jpg", "caption": "Contrast-enhanced axial, coronal and sagittal CT showing appendicitis within an inguinal hernia (Amyand hernia) with a small appendicolith.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Appendicitis_in_Leistenhernie_Amyand-Hernie_68M_-_CT_-_001.jpg"}, "questions": [{"q": "On CT enterography of active Crohn disease, engorged vasa recta lined up along the mesenteric side of an inflamed bowel segment are called the:", "options": ["Target sign", "Whirl sign", "Comb sign", "Halo sign"], "answer_index": 2, "explanation": "The comb sign reflects hypervascular mesentery next to actively inflamed bowel and supports active disease."}, {"q": "CT enterography is commonly performed in an \"enteric\" phase, about how long after the start of IV contrast injection?", "options": ["15–20 seconds", "10 minutes", "3 minutes", "45–50 seconds"], "answer_index": 3, "explanation": "Bowel-wall enhancement peaks at roughly 45–50 s, which best shows active inflammation such as Crohn disease."}, {"q": "In this case, an inflamed appendix lies within an inguinal hernia (Amyand hernia). Which outer appendiceal diameter on CT is a commonly used threshold suggesting appendicitis?", "options": ["Greater than 2 mm", "Greater than 15 mm", "Greater than 6 mm", "Greater than 25 mm"], "answer_index": 2, "explanation": "A distended appendix over about 6 mm with wall enhancement and periappendiceal fat stranding supports acute appendicitis."}]}, {"modality": "CT", "region": "pelvis", "region_label": "Pelvis", "exam": "Routine pelvis with abdomen", "image": {"file": "ct__pelvis__routine-pelvis-with-abdomen.jpg", "caption": "Axial contrast-enhanced pelvic CT from a routine abdomen/pelvis exam with a coronal reference image showing the slice position.", "credit": "Mikael Häggström, M.D.", "license": "CC0 1.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_of_a_normal_abdomen_and_pelvis,_axial_plane_240.png"}, "questions": [{"q": "The small coronal image beside this axial pelvic slice has a line drawn across it. Its purpose is to:", "options": ["Show the position of the displayed axial slice", "Measure the CT number of the bladder", "Mark the region of interest for bolus tracking", "Show the direction of table travel"], "answer_index": 0, "explanation": "A reference (localizer) line on an orthogonal image shows exactly where the current axial slice lies within the scanned volume."}, {"q": "Patients are often asked to have a moderately full bladder for pelvic CT mainly because a distended bladder:", "options": ["Lowers the required mAs", "Enhances more brightly in the arterial phase", "Prevents peristalsis artifact in the rectum", "Allows wall evaluation and displaces small bowel out of the pelvis"], "answer_index": 3, "explanation": "A collapsed bladder can mimic wall thickening; distension improves wall assessment and moves bowel loops superiorly."}, {"q": "Bilateral hip prostheses cause dense streaks across the pelvis on a routine abdomen/pelvis CT. Which measure most effectively reduces this artifact?", "options": ["Lowering the tube voltage to 80 kV", "Using a metal artifact reduction reconstruction algorithm", "Increasing the pitch to 2.0", "Using a thicker oral contrast"], "answer_index": 1, "explanation": "Iterative metal artifact reduction algorithms (often with higher kV) reduce photon-starvation and beam-hardening streaks from metal."}]}, {"modality": "CT", "region": "pelvis", "region_label": "Pelvis", "exam": "Dedicated delayed bladder", "image": {"file": "ct__pelvis__dedicated-delayed-bladder.jpg", "caption": "Delayed (excretory-phase) axial pelvic CT: dense excreted contrast layers in the dependent bladder, with a bladder urothelial carcinoma.", "credit": "James Heilman, MD", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Bladder_Transition_Cell_Carcinoma.jpg"}, "questions": [{"q": "In this image, the dense excreted contrast lies in the posterior bladder with less dense urine above it. This occurs because:", "options": ["Contrast-laden urine is denser and settles dependently before mixing", "The bladder wall absorbs contrast posteriorly", "The patient was scanned prone", "Beam hardening brightens the posterior bladder"], "answer_index": 0, "explanation": "Heavier contrast-rich urine layers in the dependent bladder; incomplete mixing can hide lesions on the nondependent wall."}, {"q": "Before delayed bladder images, the technologist may ask the patient to roll over or walk briefly. The goal is to:", "options": ["Empty the bladder completely", "Mix excreted contrast with urine so the whole bladder wall is outlined", "Speed renal clearance of contrast", "Reduce the radiation dose"], "answer_index": 1, "explanation": "Turning or ambulating mixes the contrast layer so tumors on the anterior (nondependent) wall are not missed."}, {"q": "On excretory-phase images of an opacified bladder, a urothelial carcinoma typically appears as:", "options": ["A gas-fluid level", "Contrast leaking into the perivesical fat", "A filling defect arising from the bladder wall", "A uniformly thin bladder wall"], "answer_index": 2, "explanation": "Soft-tissue tumors show as filling defects outlined by bright contrast-filled urine."}]}, {"modality": "CT", "region": "pelvis", "region_label": "Pelvis", "exam": "Retrograde CT cystogram", "image": {"file": "ct__pelvis__retrograde-ct-cystogram.jpg", "caption": "Sagittal reformation of a retrograde CT cystogram: contrast leaks from the bladder into an extraperitoneal urinoma; Foley balloon labeled.", "credit": "Akiyoshi Hagiwara, Koichiro Nishi, Keiichi Musasi Tobe, Tomohiko Asano,2 and Masamichi Hayakawa", "license": "CC BY 2.0", "page_url": "https://commons.wikimedia.org/wiki/File:Urinoma_xray.jpg"}, "questions": [{"q": "For a retrograde CT cystogram to exclude bladder rupture, dilute contrast is instilled through a Foley catheter until the bladder holds at least about:", "options": ["50 mL", "100 mL", "1,000 mL", "300–350 mL"], "answer_index": 3, "explanation": "At least ~300–350 mL (or until patient discomfort) is needed to distend the bladder enough to reveal a leak."}, {"q": "Iodinated contrast for a retrograde CT cystogram is diluted with saline (to a few percent iodine) mainly because:", "options": ["Dilution prevents bladder spasm completely", "Undiluted contrast cannot pass through a Foley catheter", "Undiluted contrast would cause streak artifacts while dilute contrast is still easily seen on CT", "Dilute contrast is absorbed faster into the bloodstream"], "answer_index": 2, "explanation": "CT is very sensitive to iodine, so dilute contrast clearly shows leaks without the beam-hardening streaks of full-strength contrast."}, {"q": "On this sagittal CT cystogram, contrast leaks into the perivesical soft tissues and collects as a urinoma below the bladder rather than outlining bowel loops. This indicates:", "options": ["Extraperitoneal bladder rupture", "Intraperitoneal bladder rupture", "A normal bladder", "Vesicoureteral reflux"], "answer_index": 0, "explanation": "Extraperitoneal rupture leaks into the perivesical and pelvic extraperitoneal spaces; intraperitoneal rupture outlines bowel and paracolic gutters."}]}, {"modality": "CT", "region": "pelvis", "region_label": "Pelvis", "exam": "Rectal contrast / colorectal", "image": {"file": "ct__pelvis__rectal-contrast-colorectal.jpg", "caption": "Axial contrast-enhanced CT of sigmoid diverticulitis with marked sigmoid wall thickening, multiple diverticula and pericolic stranding.", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:02-Sigmadivertikulitis_CT_ax_001_Verdickte_Wand.png"}, "questions": [{"q": "Rectal contrast for CT is usually instilled through a soft rectal tube with the patient in which position?", "options": ["Upright seated", "Prone Trendelenburg", "Right lateral decubitus with hips extended", "Left lateral (Sims) position"], "answer_index": 3, "explanation": "The left lateral position follows the anatomy of the rectum and sigmoid, easing tube insertion and contrast flow."}, {"q": "A key advantage of rectal contrast over oral contrast when the distal colon must be evaluated is that it:", "options": ["Gives a lower radiation dose to the bowel", "Opacifies the rectum and sigmoid within minutes, without waiting hours for oral transit", "Enhances the bowel wall more than IV contrast", "Removes the need for IV contrast"], "answer_index": 1, "explanation": "Oral contrast may take 2 hours or more to reach the left colon; rectal instillation fills the distal colon immediately."}, {"q": "This axial image shows sigmoid wall thickening with outpouchings and surrounding fat stranding. The most likely diagnosis is:", "options": ["Sigmoid diverticulitis", "Sigmoid volvulus", "Acute appendicitis", "Ischemic colitis of the cecum"], "answer_index": 0, "explanation": "Diverticula with segmental wall thickening and pericolic inflammation of the sigmoid are typical of diverticulitis."}]}, {"modality": "CT", "region": "pelvis", "region_label": "Pelvis", "exam": "CT colonography", "image": {"file": "ct__pelvis__ct-colonography.jpg", "caption": "CT colonography of a rectal mass: 3D endoluminal rendering (A) and thin axial slice (B) with the rectal tube used for gas insufflation.", "credit": "Kai Sun, Ruijuan Han, Yang Han, Xuesen Shi, Jiang Hu & Bin lu", "license": "CC BY 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_colonography_of_a_rectal_mass.jpg"}, "questions": [{"q": "The left panel (A) of this CT colonography case is which type of display?", "options": ["A curved planar reformation", "A 3D endoluminal (virtual colonoscopy) rendering", "A minimum intensity projection", "A scout radiograph"], "answer_index": 1, "explanation": "Endoluminal volume rendering simulates the optical colonoscopy view from inside the gas-distended colon."}, {"q": "Which condition is a contraindication to CT colonography?", "options": ["A history of colonic polyps", "Age over 65 years", "Acute diverticulitis or active colitis", "Incomplete optical colonoscopy"], "answer_index": 2, "explanation": "Insufflating an acutely inflamed colon raises the risk of perforation; incomplete colonoscopy is actually a common indication for CTC."}, {"q": "An intravenous antispasmodic such as glucagon or hyoscine butylbromide may be given at CT colonography to:", "options": ["Reduce radiation dose", "Tag residual stool", "Speed colonic transit", "Relax colonic spasm and improve distension"], "answer_index": 3, "explanation": "Antispasmodics reduce spasm and patient discomfort, helping achieve uniform colonic distension."}]}, {"modality": "CT", "region": "pelvis", "region_label": "Pelvis", "exam": "Bony pelvis and hip trauma", "image": {"file": "ct__pelvis__bony-pelvis-and-hip-trauma.jpg", "caption": "Axial pelvic CT in a bone window showing a complex comminuted acetabular fracture involving both columns.", "credit": "Seannovak", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Acetabular_Fracture_CT.png"}, "questions": [{"q": "This acetabular fracture is shown in a bone window. Which window settings are typical for bone?", "options": ["W 400 / L 40", "W 1500 / L −600", "W 2000 / L 500", "W 80 / L 40"], "answer_index": 2, "explanation": "A wide window with a high level (about W 1500–2500, L 300–600) shows cortex and trabecular detail; W 400/L 40 is a soft-tissue window."}, {"q": "In a patient with pelvic ring trauma, a contrast-enhanced arterial-phase CT is especially valuable to detect:", "options": ["Active arterial extravasation (contrast blush) that may need angioembolization", "Bladder stones", "Sacroiliac joint degeneration", "Bone mineral density"], "answer_index": 0, "explanation": "Pelvic fractures can tear pelvic arteries; an extravasation blush identifies bleeding that may need embolization."}, {"q": "A dedicated CT of the bony pelvis for trauma typically extends from:", "options": ["The diaphragm to the iliac crests", "L1 to the sacral promontory", "The pubic symphysis to the knees", "The iliac crests through the proximal femurs (below the lesser trochanters)"], "answer_index": 3, "explanation": "Coverage must include the whole pelvic ring, acetabula and proximal femurs to capture associated hip fractures."}]}, {"modality": "CT", "region": "spine", "region_label": "Spine", "exam": "Cervical spine (trauma)", "image": {"file": "ct__spine__cervical-spine-trauma.jpg", "caption": "Coronal and sagittal CT reformations of the cervical spine showing a nondisplaced type II odontoid (dens) fracture.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Densfraktur_Typ_2_nach_Anderson_und_DAlonzo_81W_-_CT_coronar_und_sagittal_-_001.jpg"}, "questions": [{"q": "On these coronal and sagittal reformats, the fracture crosses the base of the dens at its junction with the C2 body. In the Anderson–D’Alonzo classification this is a:", "options": ["Type I", "Type II", "Type III", "Hangman fracture"], "answer_index": 1, "explanation": "Type II crosses the base of the dens; type I is an avulsion of the tip and type III extends into the C2 body."}, {"q": "For cervical spine trauma CT, which reconstruction set is essential in addition to the axial images?", "options": ["Sagittal and coronal MPRs in a bone algorithm from thin axial sections", "A single 10 mm axial set in a soft-tissue kernel", "Only 3D surface renderings", "Minimum intensity projections in a lung window"], "answer_index": 0, "explanation": "Thin bone-algorithm sections with sagittal and coronal MPRs show alignment and fractures parallel to the axial plane."}, {"q": "A trauma patient arrives for cervical spine CT wearing a rigid cervical collar. The technologist should:", "options": ["Remove the collar to improve image quality", "Leave the collar in place and keep the spine immobilized unless a physician clears it", "Flex the neck to straighten the cervical lordosis", "Turn the head to the side to reduce shoulder artifact"], "answer_index": 1, "explanation": "Spinal immobilization is maintained until injury is excluded; modern collars are radiolucent enough for diagnostic CT."}]}, {"modality": "CT", "region": "spine", "region_label": "Spine", "exam": "Thoracic spine", "image": {"file": "ct__spine__thoracic-spine.jpg", "caption": "Coronal, sagittal and axial CT reformations of the thoracic spine showing a partial dorsal butterfly vertebra at T11.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Partieller_dorsaler_Schmetterlingswirbel_BWK_11_57W_-_CT_coronar_sagittal_und_axial_-_001.jpg"}, "questions": [{"q": "This coronal reformat shows a partial butterfly vertebra at T11. A butterfly vertebra results from:", "options": ["An osteoporotic compression fracture", "A burst fracture with retropulsion", "Failure of fusion of the two lateral halves of the vertebral body during development", "Metastatic destruction of the pedicles"], "answer_index": 2, "explanation": "It is a congenital anomaly from a persistent sagittal cleft; recognizing it avoids misdiagnosis as a fracture."}, {"q": "A flexion-distraction (Chance) fracture at the thoracolumbar junction is classically associated with:", "options": ["Diving into shallow water", "A fall onto an outstretched hand", "Osteoporosis without trauma", "A lap-belt injury, often with associated bowel or mesenteric injury"], "answer_index": 3, "explanation": "Lap-belt flexion over the belt distracts the posterior elements, and the same force can injure bowel and mesentery."}, {"q": "To label thoracic vertebral levels reliably on CT, the most dependable method is to:", "options": ["Count upward from the sacrum on an axial image", "Use the level of the aortic arch as T8", "Count from C2 downward on a sagittal image or correlate with rib articulations", "Assume the lowest rib-bearing vertebra is always T12"], "answer_index": 2, "explanation": "Transitional anatomy and variant rib counts make level-labeling error-prone; counting from C2 or correlating with ribs reduces wrong-level errors."}]}, {"modality": "CT", "region": "spine", "region_label": "Spine", "exam": "Lumbosacral spine", "image": {"file": "ct__spine__lumbosacral-spine.jpg", "caption": "Sagittal CT reformation of the lower lumbar spine showing an L5 pars interarticularis defect (spondylolysis).", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:01-Spondylolyse_L5S1_CT_sagittal_001.jpg"}, "questions": [{"q": "On this sagittal image, a lucent defect crosses the pars interarticularis of L5. This condition is called:", "options": ["Spondylolysis", "Spondylosis", "Schmorl node", "Baastrup disease"], "answer_index": 0, "explanation": "Spondylolysis is a defect of the pars interarticularis, most often at L5, and may lead to spondylolisthesis."}, {"q": "With modern multidetector CT, lumbar disc levels are usually imaged by:", "options": ["Tilting the gantry separately for each disc space", "Using 10 mm axial step-and-shoot slices", "Scanning only the L4–L5 and L5–S1 levels", "Acquiring a continuous helical volume and creating oblique MPRs aligned to each disc"], "answer_index": 3, "explanation": "Volumetric helical data allow reformats in any plane, replacing the older angled-gantry technique."}, {"q": "For lumbar spine CT, a sponge or support is placed under the patient’s knees mainly to:", "options": ["Increase lumbar lordosis", "Reduce lumbar lordosis and improve comfort", "Raise the spine to isocenter", "Shield the gonads"], "answer_index": 1, "explanation": "Flexing the knees flattens the lumbar curve, straightening the spine relative to the scan plane and easing back strain."}]}, {"modality": "CT", "region": "spine", "region_label": "Spine", "exam": "Postmyelogram CT", "image": {"file": "ct__spine__postmyelogram-ct.jpg", "caption": "Sagittal post-myelogram CT of the lumbar spine with intrathecal contrast outlining the thecal sac and cauda equina.", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Post-Myelo-CT.jpg"}, "questions": [{"q": "On this sagittal post-myelogram image, the bright column outlining the thecal sac and nerve roots is contrast within the:", "options": ["Subarachnoid space", "Epidural space", "Intervertebral disc", "Central canal of the spinal cord"], "answer_index": 0, "explanation": "Myelographic contrast is injected intrathecally into the subarachnoid space, outlining the cord, conus and nerve roots."}, {"q": "CT myelography is most often chosen instead of MRI when:", "options": ["Soft-tissue contrast must be maximized", "MRI is contraindicated or degraded by spinal hardware", "No lumbar puncture can be performed", "The patient is pregnant"], "answer_index": 1, "explanation": "CT myelography outlines the thecal sac and nerve roots in patients with pacemakers or metal fixation that prevent diagnostic MRI."}, {"q": "After intrathecal contrast injection, the patient is kept with the head elevated until and during transfer to CT mainly to:", "options": ["Keep contrast in the epidural space", "Speed absorption of contrast", "Prevent contrast from flowing intracranially", "Reduce lumbar lordosis"], "answer_index": 2, "explanation": "Keeping the head up limits intracranial spread of contrast, which can cause headache, nausea or rarely seizures."}]}, {"modality": "CT", "region": "upper_extremity", "region_label": "Upper Extremity / Shoulder", "exam": "Shoulder", "image": {"file": "ct__upper_extremity__shoulder.jpg", "caption": "Labeled axial CT of the left shoulder showing a comminuted fracture of the humeral head with surrounding scapular and rotator cuff anatomy.", "credit": "Cerevisae", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:CT_scan_of_left_shoulder_head_of_humerus_fracture.png"}, "questions": [{"q": "On this labeled axial shoulder image, which rotator cuff muscle lies along the anterior (costal) surface of the scapula?", "options": ["Infraspinatus", "Supraspinatus", "Teres minor", "Subscapularis"], "answer_index": 3, "explanation": "Subscapularis lies on the anterior surface of the scapula and inserts on the lesser tuberosity; infraspinatus is posterior."}, {"q": "Sagittal oblique reformations of the shoulder are prescribed:", "options": ["Parallel to the clavicle", "Perpendicular to the humeral shaft", "Parallel to the glenoid articular surface", "Along the spine of the scapula"], "answer_index": 2, "explanation": "Sagittal obliques parallel to the glenoid face show the glenoid en face; coronal obliques follow the supraspinatus."}, {"q": "After shoulder dislocation, glenoid bone loss is best measured on a 3D reconstruction in which:", "options": ["The humeral head is digitally subtracted to show the glenoid en face", "The clavicle is removed", "Only soft tissues are displayed", "Both shoulders are superimposed"], "answer_index": 0, "explanation": "Removing the humeral head allows an en face view of the glenoid to quantify anterior-inferior bone loss for surgical planning."}]}, {"modality": "CT", "region": "upper_extremity", "region_label": "Upper Extremity / Shoulder", "exam": "Elbow", "image": {"file": "ct__upper_extremity__elbow.jpg", "caption": "Two sagittal CT reformations of the elbow showing a radial head fracture with an impaction defect of the posterior capitellum after radial head dislocation.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Kleine_Osborne-Cotterill-Laesion_mit_Radiuskoepfchenfraktur_nach_Luxation_57M_-_CT_sagittal_-_001.jpg"}, "questions": [{"q": "On these sagittal elbow reformats, the radial head articulates with which part of the distal humerus?", "options": ["Trochlea", "Medial epicondyle", "Olecranon fossa", "Capitulum (capitellum)"], "answer_index": 3, "explanation": "The radial head articulates with the capitellum; the trochlea articulates with the ulna’s trochlear notch."}, {"q": "The \"terrible triad\" of the elbow, often evaluated with CT, consists of posterior elbow dislocation with fractures of the:", "options": ["Olecranon and medial epicondyle", "Radial head and coronoid process", "Capitellum and lateral epicondyle", "Distal humeral shaft and olecranon"], "answer_index": 1, "explanation": "Elbow dislocation with radial head and coronoid fractures is highly unstable; CT defines fragment size for surgical planning."}, {"q": "Which is the most common elbow fracture in adults?", "options": ["Radial head fracture", "Supracondylar fracture", "Olecranon fracture", "Coronoid process fracture"], "answer_index": 0, "explanation": "Radial head fractures, usually from a fall on an outstretched hand, are the most common adult elbow fracture; supracondylar fractures dominate in children."}]}, {"modality": "CT", "region": "upper_extremity", "region_label": "Upper Extremity / Shoulder", "exam": "Wrist and hand", "image": {"file": "ct__upper_extremity__wrist-and-hand.jpg", "caption": "Coronal CT reformation of the wrist showing scaphoid nonunion (outlined scaphoid with sclerotic, non-united fracture margins).", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Scaphoidpseudarthtrose_CT_coronar.png"}, "questions": [{"q": "On a normal sagittal CT reformation of the wrist, the distal radius, lunate and capitate should:", "options": ["Form a 90° angle at the lunate", "Lie in a straight, colinear alignment", "Overlap so the lunate is hidden", "Be separated by more than 5 mm"], "answer_index": 1, "explanation": "Loss of radius–lunate–capitate alignment on sagittal images suggests perilunate or lunate dislocation or carpal instability."}, {"q": "This coronal image shows a non-united scaphoid fracture with sclerotic margins. Because of the scaphoid’s retrograde blood supply, the main risk is:", "options": ["Ulnar nerve palsy", "Avascular necrosis of the distal pole", "Avascular necrosis of the proximal pole", "Carpal boss formation"], "answer_index": 2, "explanation": "Blood enters the scaphoid distally, so waist fractures can devascularize the proximal pole."}, {"q": "After scaphoid fixation or casting, CT is often preferred to judge healing because it best shows:", "options": ["Soft-tissue swelling", "Bone marrow edema", "Ligament tears", "Bridging trabeculae across the fracture line"], "answer_index": 3, "explanation": "Thin-section CT directly shows osseous bridging (union) or persistent gaps (nonunion) better than radiographs."}]}, {"modality": "CT", "region": "upper_extremity", "region_label": "Upper Extremity / Shoulder", "exam": "Post-arthrogram (shoulder, wrist)", "image": {"file": "ct__upper_extremity__post-arthrogram-shoulder-wrist.jpg", "caption": "Axial CT arthrogram of the shoulder after a Latarjet coracoid transfer: intra-articular contrast outlines the joint; fixation screws in the anterior glenoid.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Latarjet-Korakoidtransfer_mit_CT-Athrographie_34M_-_CR_und_CT-Athrographie_ax_-_001.jpg"}, "questions": [{"q": "In this patient, CT arthrography was chosen over MR arthrography. CT arthrography is especially useful when:", "options": ["No joint injection is possible", "Cartilage detail is not needed", "The patient has metal hardware or an MRI contraindication", "The patient cannot lie still for 30 seconds"], "answer_index": 2, "explanation": "CT arthrography is the alternative when MRI is contraindicated or degraded by metal, as with the screws shown here."}, {"q": "Iodinated contrast for single-contrast CT arthrography is usually diluted because overly dense contrast:", "options": ["Causes beam-hardening and blooming that obscure cartilage and labral surfaces", "Is absorbed too slowly", "Cannot be injected through a fine needle", "Increases radiation dose to the joint"], "answer_index": 0, "explanation": "Very dense contrast creates artifacts at the contrast–cartilage interface; dilution preserves surface detail."}, {"q": "In wrist CT arthrography with injection into the radiocarpal joint, contrast passing into the midcarpal joint indicates a tear of the:", "options": ["Triangular fibrocartilage complex only", "Ulnar collateral ligament of the thumb", "Flexor retinaculum", "Scapholunate or lunotriquetral interosseous ligament"], "answer_index": 3, "explanation": "The intrinsic interosseous ligaments separate the radiocarpal and midcarpal compartments; communication means a defect."}]}, {"modality": "CT", "region": "upper_extremity", "region_label": "Upper Extremity / Shoulder", "exam": "Upper extremity CTA", "image": {"file": "ct__upper_extremity__upper-extremity-cta.jpg", "caption": "Volume-rendered CT angiogram of both hands showing the palmar arches and digital arteries.", "credit": "MBq at German Wikipedia", "license": "Public domain", "page_url": "https://commons.wikimedia.org/wiki/File:CT-Angiografie-Haende.jpg"}, "questions": [{"q": "For a unilateral upper extremity CTA, IV contrast is ideally injected:", "options": ["Into the symptomatic arm", "Into the contralateral arm or a lower-extremity vein", "Directly into the radial artery", "Through a central venous catheter in the symptomatic side"], "answer_index": 1, "explanation": "Dense contrast in the veins of the arm being studied causes streak artifact that can obscure adjacent arteries."}, {"q": "Besides volume rendering as shown here, which display best summarizes small contrast-filled hand arteries by showing the brightest voxel along each ray?", "options": ["Maximum intensity projection", "Minimum intensity projection", "Shaded surface display of bone", "Average intensity projection"], "answer_index": 0, "explanation": "MIP keeps the highest attenuation along each ray, highlighting opacified vessels (calcium and bone also appear bright)."}, {"q": "For suspected thoracic outlet syndrome, upper extremity CTA is often performed:", "options": ["Only with the arm at the side", "With the arm at the side and then elevated/abducted to show dynamic compression", "With the patient upright in the scanner", "Without IV contrast"], "answer_index": 1, "explanation": "Comparing neutral and provocative arm positions reveals positional compression of the subclavian artery or vein."}]}, {"modality": "CT", "region": "lower_extremity", "region_label": "Lower Extremity / Hip", "exam": "Hip", "image": {"file": "ct__lower_extremity__hip.jpg", "caption": "Hip CT (axial, sagittal reformation and 3D volume rendering) after traumatic posterior hip dislocation with a small femoral head impaction.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Traumatische_hintere_Hueftluxation_links_45M_-_CT_-_001.jpg"}, "questions": [{"q": "This patient had a traumatic hip dislocation. The most common direction of traumatic hip dislocation is:", "options": ["Anterior", "Inferior", "Posterior", "Central"], "answer_index": 2, "explanation": "About 90% of traumatic hip dislocations are posterior, typically from a dashboard injury with the hip flexed."}, {"q": "CT after reduction of a dislocated hip is mainly used to look for:", "options": ["Bone mineral density", "Hip joint effusion volume only", "Femoral artery calcification", "Intra-articular bone fragments, acetabular rim or femoral head fractures, and joint incongruity"], "answer_index": 3, "explanation": "Retained fragments or a nonconcentric reduction can require surgery and must be excluded after closed reduction."}, {"q": "On hip CT for femoroacetabular impingement, the alpha angle measured on oblique or radial reformations assesses:", "options": ["Femoral shaft bowing", "Acetabular depth", "Asphericity at the femoral head–neck junction (cam deformity)", "Sacroiliac joint width"], "answer_index": 2, "explanation": "An increased alpha angle indicates loss of the normal head–neck offset, the hallmark of cam-type impingement."}]}, {"modality": "CT", "region": "lower_extremity", "region_label": "Lower Extremity / Hip", "exam": "Knee (tibial plateau)", "image": {"file": "ct__lower_extremity__knee-tibial-plateau.jpg", "caption": "3D volume-rendered CT of the knee showing a depressed lateral tibial plateau fracture.", "credit": "LottieLattes", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Lateral_Tibial_Plateau_fracture_CT_with_Depression.jpg"}, "questions": [{"q": "This 3D image shows depression of the lateral tibial plateau articular surface. A pure lateral plateau depression without a split fragment is which Schatzker type?", "options": ["Type III", "Type I", "Type IV", "Type VI"], "answer_index": 0, "explanation": "Schatzker I is a lateral split, II split-depression, III pure depression, IV medial plateau, V bicondylar, VI metaphyseal–diaphyseal dissociation."}, {"q": "Knee CT for plateau fractures uses a small display field of view centered on the injured knee mainly to:", "options": ["Lower the tube current", "Shorten scan time", "Include the contralateral knee for comparison", "Increase spatial resolution by reducing pixel size"], "answer_index": 3, "explanation": "A smaller DFOV with the same matrix gives smaller pixels and sharper detail of fracture lines and articular steps."}, {"q": "On coronal and sagittal reformations of a tibial plateau fracture, which measurement most directly guides the decision for surgery?", "options": ["Patellar height ratio", "Depth of articular surface depression in millimeters", "Femoral anteversion angle", "Hounsfield units of the joint effusion"], "answer_index": 1, "explanation": "The amount of articular step-off or depression (and condylar widening) determines whether operative elevation and fixation are needed."}]}, {"modality": "CT", "region": "lower_extremity", "region_label": "Lower Extremity / Hip", "exam": "Ankle and foot", "image": {"file": "ct__lower_extremity__ankle-and-foot.jpg", "caption": "Sagittal CT reformation of the hindfoot showing a comminuted intra-articular calcaneal fracture (circled).", "credit": "James Heilman, MD", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:CalcanealfractCT.png"}, "questions": [{"q": "For hindfoot CT after a calcaneal fracture, both feet are commonly scanned together with the soles flat against a footboard because this:", "options": ["Gives standardized, symmetric positioning for reformations and side-to-side comparison", "Eliminates the need for reformations", "Lowers dose to the injured foot only", "Allows IV contrast to reach both feet"], "answer_index": 0, "explanation": "Symmetric positioning makes reformations reproducible and lets the uninjured side serve as a reference."}, {"q": "On this sagittal image of a calcaneal fracture, collapse and flattening of the posterior facet would decrease which radiographic angle?", "options": ["Baumann angle", "Böhler angle", "Q angle", "Carrying angle"], "answer_index": 1, "explanation": "Böhler angle (normally ~20–40°) decreases when the posterior facet is depressed; the angle of Gissane tends to increase."}, {"q": "Because calcaneal fractures usually result from axial loading such as a fall from height, which associated injury should be specifically excluded?", "options": ["Dens fracture", "Scaphoid fracture", "Thoracolumbar spine compression fracture", "Distal clavicle fracture"], "answer_index": 2, "explanation": "The same axial force can compress the thoracolumbar spine, so imaging of the spine is often recommended."}]}, {"modality": "CT", "region": "lower_extremity", "region_label": "Lower Extremity / Hip", "exam": "Post-arthrogram knee", "image": {"file": "ct__lower_extremity__post-arthrogram-knee.jpg", "caption": "Knee CT arthrogram (coronal and axial): intra-articular contrast outlines the cartilage, showing high-grade retropatellar and femoral chondromalacia.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Arthro-CT_mit_drittgradiger_Chondromalazie_39W_-_CT_coronar_und_axial_-_001.jpg"}, "questions": [{"q": "On the axial CT arthrogram image, contrast fills a deep defect in the patellar cartilage. This finding represents:", "options": ["A meniscal tear", "A Baker (popliteal) cyst", "An anterior cruciate ligament tear", "High-grade chondral (cartilage) loss"], "answer_index": 3, "explanation": "CT arthrography outlines articular cartilage with contrast; contrast entering a deep defect indicates advanced chondromalacia."}, {"q": "On knee CT arthrography, a meniscal tear typically appears as:", "options": ["Calcification of the meniscus", "Increased meniscal enhancement after IV contrast", "Contrast extending into or through the meniscal substance", "Absence of joint effusion"], "answer_index": 2, "explanation": "Normal menisci are uniformly soft-tissue dense; contrast tracking into the meniscus signifies a tear."}, {"q": "After intra-articular injection and before scanning a knee CT arthrogram, the patient is usually asked to:", "options": ["Gently flex and extend the knee or walk briefly to distribute contrast", "Remain completely still for 30 minutes", "Drink 1 L of water", "Lie prone with the knee flexed 90°"], "answer_index": 0, "explanation": "Moving the joint spreads contrast into all recesses so cartilage and menisci are evenly outlined."}]}, {"modality": "CT", "region": "lower_extremity", "region_label": "Lower Extremity / Hip", "exam": "Lower extremity CTA runoff", "image": {"file": "ct__lower_extremity__lower-extremity-cta-runoff.jpg", "caption": "Volume-rendered CT angiogram of the abdominal aorta, pelvis and thighs in a patient with Buerger disease (thromboangiitis obliterans).", "credit": "Milorad Dimic MD", "license": "GFDL 1.2+", "page_url": "https://commons.wikimedia.org/wiki/File:M.Buerger_1.JPG"}, "questions": [{"q": "A typical scan range for a lower extremity CTA runoff is:", "options": ["From the knees through the toes", "From the aortic arch to the knees", "From the iliac crests to the ankles only", "From the renal arteries (or above) through the feet"], "answer_index": 3, "explanation": "Runoff covers inflow (abdominal aorta and iliacs), outflow (femoropopliteal) and runoff (tibial and pedal) vessels."}, {"q": "Heavily calcified tibial arteries make lumen assessment difficult on MIP images. Which reformation best evaluates the true lumen along the vessel?", "options": ["Thick-slab MIP", "Curved planar reformation through the vessel centerline", "Shaded surface display", "Scout (topogram) image"], "answer_index": 1, "explanation": "CPRs follow the vessel and show the lumen in cross-section, so stenoses can be judged despite calcium that hides the lumen on MIP."}, {"q": "This runoff angiogram is from a patient with thromboangiitis obliterans (Buerger disease). This condition is most strongly associated with:", "options": ["Tobacco use", "Marfan syndrome", "Long-term steroid use", "Pregnancy"], "answer_index": 0, "explanation": "Buerger disease is a nonatherosclerotic inflammatory occlusive disease of small and medium arteries, almost exclusively in smokers."}]}, {"modality": "MRI", "region": "head", "region_label": "Head / Brain", "exam": "Routine brain", "image": {"file": "mri__head__routine-brain.jpg", "caption": "Axial T2-weighted brain MRI at the level of the basal ganglia and lateral ventricles.", "credit": "Afiller at English Wikipedia", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:MRI_T2_Brain_axial_image.jpg"}, "questions": [{"q": "On this axial T2-weighted brain image, CSF in the ventricles is bright. Which spin-echo parameter combination produces T2 weighting?", "options": ["Short TR and short TE", "Long TR and short TE", "Long TR and long TE", "Short TR and long TE"], "answer_index": 2, "explanation": "A long TR minimizes T1 differences and a long TE lets T2 decay differences develop, so long-T2 fluid such as CSF stays bright."}, {"q": "On this axial T2-weighted image, white matter is darker than cortical gray matter. Why?", "options": ["Myelinated white matter has less free water and a shorter T2", "White matter has a longer T2 than gray matter", "Gray matter contains more fat", "The receive coil is less sensitive to white matter"], "answer_index": 0, "explanation": "Myelin's lipid and protein content restricts free water, shortening T2, so adult white matter is darker than gray matter on T2-weighted images."}, {"q": "Which sequence is added to a routine brain protocol to show small hemorrhages, blood products and calcification?", "options": ["STIR", "Fast spin-echo proton density", "T1 FLAIR", "Gradient-echo T2* or susceptibility-weighted imaging (SWI)"], "answer_index": 3, "explanation": "Gradient echo has no 180-degree refocusing pulse, so susceptibility effects from hemosiderin, deoxyhemoglobin and calcium cause visible signal loss."}]}, {"modality": "MRI", "region": "head", "region_label": "Head / Brain", "exam": "Brain for MS", "image": {"file": "mri__head__brain-for-ms.jpg", "caption": "Axial T2-weighted brain MRI showing multiple hyperintense white matter lesions in multiple sclerosis.", "credit": "James Heilman, MD", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:MSMRI.png"}, "questions": [{"q": "Under the McDonald criteria, dissemination in space can be shown by T2 lesions in which locations?", "options": ["Basal ganglia, thalamus, pituitary and orbit", "Periventricular, cortical/juxtacortical, infratentorial and spinal cord", "Only the frontal and parietal lobes", "Corpus callosum and cerebellar vermis only"], "answer_index": 1, "explanation": "MS lesions in at least two of these characteristic regions support dissemination in space, so MS protocols cover the whole brain and often the cord."}, {"q": "What is the main advantage of a 3D isotropic FLAIR sequence in an MS protocol?", "options": ["It needs no CSF suppression", "Thin contiguous slices that can be reformatted in any plane, improving small-lesion detection", "It replaces post-contrast imaging", "It shortens T1 of plaques"], "answer_index": 1, "explanation": "Isotropic 3D data avoid slice gaps and partial volume, so small plaques are easier to detect and compare on follow-up."}, {"q": "What delay between gadolinium injection and the post-contrast T1 acquisition is generally recommended to maximize detection of enhancing MS lesions?", "options": ["None; scan during the arterial phase", "Exactly 20 seconds", "24 hours", "At least about 5 minutes"], "answer_index": 3, "explanation": "Enhancement of demyelinating lesions builds over several minutes, so a short delay of about 5 minutes or more improves lesion conspicuity."}]}, {"modality": "MRI", "region": "head", "region_label": "Head / Brain", "exam": "Brain for seizure", "image": {"file": "mri__head__brain-for-seizure.jpg", "caption": "Coronal T2-weighted MRI comparing the hippocampi (circled); the left hippocampus is small, consistent with hippocampal sclerosis.", "credit": "Uhomachinky", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Left_Hippocampal_Sclerosis_on_MRI.jpg"}, "questions": [{"q": "This coronal image is shown in standard radiological display. On which side of the image does the patient's left hippocampus appear?", "options": ["On the viewer's right", "On the viewer's left", "At the top of the image", "It cannot be determined"], "answer_index": 0, "explanation": "Radiological convention displays images as if facing the patient, so the patient's left is on the viewer's right."}, {"q": "Which sequence suppresses both CSF and white matter to highlight cortical gray matter abnormalities in epilepsy or MS?", "options": ["STIR", "Time-of-flight", "Double inversion recovery (DIR)", "Single-shot fast spin echo"], "answer_index": 2, "explanation": "Two inversion pulses null CSF and white matter, leaving gray matter and lesions within it conspicuous."}, {"q": "Why do seizure protocols use thin slices or 3D isotropic sequences?", "options": ["To shorten the exam", "To reduce SAR", "To eliminate the need for contrast", "To detect small cortical malformations such as focal cortical dysplasia"], "answer_index": 3, "explanation": "Subtle epileptogenic lesions like focal cortical dysplasia can be missed on thick slices; thin or isotropic data allow reformatting in any plane."}]}, {"modality": "MRI", "region": "head", "region_label": "Head / Brain", "exam": "Pituitary", "image": {"file": "mri__head__pituitary.jpg", "caption": "Coronal and sagittal post-contrast T1-weighted MRI of the sella showing the enhancing pituitary gland (1 T).", "credit": "Foma39", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Sella_mri-contra.jpg"}, "questions": [{"q": "On these images, the optic chiasm lies just above the pituitary. A macroadenoma growing upward and compressing the chiasm classically causes:", "options": ["Monocular blindness in one eye only", "Hearing loss", "Bitemporal hemianopia", "Facial nerve palsy"], "answer_index": 2, "explanation": "Crossing nasal retinal fibers in the chiasm carry the temporal visual fields, so suprasellar compression produces loss of both temporal fields."}, {"q": "Which slice thickness is typical for dedicated pituitary imaging?", "options": ["8-10 mm with a large field of view", "2-3 mm with a small field of view", "5 mm with a 50% gap", "15 mm slabs"], "answer_index": 1, "explanation": "The gland is only about 1 cm tall, so thin, small-FOV coronal and sagittal slices are needed to resolve small lesions."}, {"q": "For dynamic pituitary imaging, the gadolinium dose is often:", "options": ["Reduced, commonly to about half the standard dose", "Tripled to maximize enhancement", "Given orally", "Omitted entirely"], "answer_index": 0, "explanation": "A lower dose avoids overwhelming enhancement that could mask a small, slowly enhancing microadenoma."}]}, {"modality": "MRI", "region": "head", "region_label": "Head / Brain", "exam": "Internal auditory canals", "image": {"file": "mri__head__internal-auditory-canals.jpg", "caption": "Axial post-contrast T1-weighted MRI showing an enhancing schwannoma in the left internal auditory canal.", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Akustikus-Schwannon_links_intrameatal_MRT_T1KM_axial.jpg"}, "questions": [{"q": "This axial post-contrast T1 image shows a small enhancing mass within the left internal auditory canal. What is the most likely diagnosis?", "options": ["Meningioma of the falx", "Pituitary macroadenoma", "Vestibular schwannoma", "Cholesteatoma of the external canal"], "answer_index": 2, "explanation": "An enhancing intracanalicular mass in an adult is most often a vestibular schwannoma (acoustic neuroma)."}, {"q": "Which slice thickness is appropriate for high-resolution 3D T2 imaging of the internal auditory canals?", "options": ["About 0.5-1 mm", "5 mm", "8 mm with a gap", "10 mm"], "answer_index": 0, "explanation": "The facial and vestibulocochlear nerves are only a few millimeters across, so submillimeter slices are needed to see them and small lesions."}, {"q": "Which cranial nerves pass through the internal auditory canal?", "options": ["Trigeminal (CN V) and abducens (CN VI)", "Glossopharyngeal (CN IX) and vagus (CN X)", "Optic (CN II) and oculomotor (CN III)", "Facial (CN VII) and vestibulocochlear (CN VIII)"], "answer_index": 3, "explanation": "The IAC carries CN VII and the cochlear and vestibular divisions of CN VIII, along with the labyrinthine artery."}]}, {"modality": "MRI", "region": "head", "region_label": "Head / Brain", "exam": "Orbits", "image": {"file": "mri__head__orbits.jpg", "caption": "Axial T2-weighted MRI of the orbits in Graves' ophthalmopathy showing enlarged extraocular muscles and proptosis.", "credit": "Huy A Tran and Glenn EM Reeves", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:MRI_Graves%27_Ophthalmopathy.jpg"}, "questions": [{"q": "This axial orbital image shows enlarged extraocular muscles in thyroid eye disease. Which pattern is typical?", "options": ["Enlargement of the tendons with normal muscle bellies", "Enlargement of the muscle bellies with sparing of the tendon insertions", "Optic nerve sheath calcification", "A single enhancing mass at the orbital apex"], "answer_index": 1, "explanation": "Thyroid orbitopathy enlarges the muscle bellies (inferior and medial rectus most often) while sparing the tendons, unlike orbital myositis."}, {"q": "Why is fat suppression used for orbital MRI, especially after contrast?", "options": ["It increases SNR more than any other option", "Bright orbital fat would otherwise hide edema or enhancement of the optic nerve and muscles", "It removes susceptibility artifact from the sinuses", "It shortens the scan time by half"], "answer_index": 1, "explanation": "Orbital fat is very bright on T1 and fast spin-echo T2; suppressing it lets abnormal enhancement or edema stand out."}, {"q": "Which patient instruction best reduces motion artifact during an orbit exam?", "options": ["Look around the room between sequences", "Blink rapidly during acquisition", "Hold the breath for each sequence", "Keep the eyes gently closed and still during each sequence"], "answer_index": 3, "explanation": "Eye movement causes ghosting across the orbits; closing the eyes and keeping them still is simple and effective."}]}, {"modality": "MRI", "region": "head", "region_label": "Head / Brain", "exam": "MRA/MRV head", "image": {"file": "mri__head__mra-mrv-head.jpg", "caption": "Maximum intensity projection (MIP) of an intracranial MR angiogram showing the circle of Willis.", "credit": "Nevit Dilmen (talk)", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:MRA_102014.png"}, "questions": [{"q": "This MIP of the circle of Willis comes from a 3D TOF MRA. Why is a saturation band placed superior to the imaging slab?", "options": ["To suppress signal from venous blood flowing down into the slab", "To boost arterial inflow from below", "To null CSF signal", "To remove fat signal from the scalp"], "answer_index": 0, "explanation": "Venous blood in the sinuses flows toward the slab from above; saturating it leaves the inflowing arteries bright."}, {"q": "Why is intracranial TOF MRA often acquired as multiple overlapping thin 3D slabs (MOTSA)?", "options": ["To remove the need for a saturation band", "To make veins brighter than arteries", "To limit saturation of inflowing blood within each slab while keeping 3D resolution", "To shorten T2 of blood"], "answer_index": 2, "explanation": "Blood loses signal the farther it travels in a thick slab; thinner overlapping slabs keep distal vessels bright."}, {"q": "On TOF MRA, a subacute hematoma or thrombus can appear bright and mimic flow. Why?", "options": ["It has a long T2*", "It flows faster than arterial blood", "Gadolinium is always present in clots", "Methemoglobin shortens T1, so it stays bright on the T1-weighted TOF images"], "answer_index": 3, "explanation": "TOF images are heavily T1-weighted, so any short-T1 tissue (methemoglobin, fat) can shine through on the MIP."}]}, {"modality": "MRI", "region": "head", "region_label": "Head / Brain", "exam": "Brain perfusion", "image": {"file": "mri__head__brain-perfusion.jpg", "caption": "MR perfusion color maps (CBF, CBV and time-to-drain) in cerebral infarction.", "credit": "edit Shazia Mirza and Sankalp Gokhale See also source article for additional image creators.", "license": "CC BY 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:MR_perfusion_in_cerebral_infarction.png"}, "questions": [{"q": "On these color maps, which parameter represents the volume of blood in a given amount of brain tissue?", "options": ["Cerebral blood flow (CBF)", "Time to drain (TTD)", "Cerebral blood volume (CBV)", "Apparent diffusion coefficient (ADC)"], "answer_index": 2, "explanation": "CBV is blood volume per unit of tissue; CBF is volume per unit time, and transit-time maps show how long blood takes to pass through."}, {"q": "Which relationship (central volume principle) links the main perfusion parameters?", "options": ["CBV = CBF / MTT", "CBF = CBV / MTT", "MTT = CBF x CBV", "CBF = CBV x MTT"], "answer_index": 1, "explanation": "Mean transit time equals blood volume divided by flow, so any two parameters determine the third."}, {"q": "In acute stroke, a perfusion deficit that is much larger than the DWI lesion suggests:", "options": ["Potentially salvageable penumbra", "The whole area is already infarcted", "A perfusion artifact only", "Old hemorrhage"], "answer_index": 0, "explanation": "The DWI lesion approximates the core; hypoperfused tissue beyond it may still be rescued by reperfusion."}]}, {"modality": "MRI", "region": "head", "region_label": "Head / Brain", "exam": "MR spectroscopy", "image": {"file": "mri__head__mr-spectroscopy.jpg", "caption": "Single-voxel proton MR spectroscopy: voxel placement on brain MR images (left) and the resulting spectrum with choline, creatine and NAA peaks (right).", "credit": "Boucard CC, Hoogduin JM, van der Grond J, Cornelissen FW", "license": "CC BY 2.5", "page_url": "https://commons.wikimedia.org/wiki/File:PLoS_ONE_0000222_g001_MRS.jpg"}, "questions": [{"q": "In this single-voxel spectrum, Cho, Cr and NAA peaks are labeled. Which TE is used for a short-TE spectrum that also shows myo-inositol and glutamate/glutamine?", "options": ["About 288 ms", "About 1,000 ms", "About 20-35 ms", "About 2,000 ms"], "answer_index": 2, "explanation": "Short-TE spectra preserve short-T2 metabolites such as myo-inositol and Glx, while long TEs give a cleaner baseline with fewer peaks."}, {"q": "Why is water suppression (for example, CHESS) applied in proton MRS?", "options": ["The water signal is thousands of times larger than metabolite signals", "Water causes chemical shift artifact on images", "It removes lipid peaks from the scalp", "It shortens the TR"], "answer_index": 0, "explanation": "Without suppression, the huge water peak would swamp the millimolar metabolite peaks."}, {"q": "Compared with single-voxel spectroscopy, what is the main advantage of multivoxel chemical shift imaging (CSI)?", "options": ["It needs no water suppression", "It is less sensitive to shimming", "It always takes less time", "It samples a grid of voxels so regional metabolite differences can be mapped"], "answer_index": 3, "explanation": "CSI acquires spectra from many voxels at once, showing heterogeneity across a lesion and nearby tissue, at the cost of more complex shimming and longer scans."}]}, {"modality": "MRI", "region": "head", "region_label": "Head / Brain", "exam": "CSF flow study", "image": null, "questions": [{"q": "In normal pressure hydrocephalus, aqueductal CSF flow on phase-contrast imaging is often:", "options": ["Completely absent", "Increased (hyperdynamic) stroke volume", "Exactly normal in all cases", "Reversed only during inspiration"], "answer_index": 1, "explanation": "A hyperdynamic aqueductal flow void and high stroke volume have been reported in NPH, though results support rather than establish the diagnosis."}, {"q": "On a phase-contrast phase image, how is flow direction displayed?", "options": ["By color only on the magnitude image", "By pixel brightness: one direction bright, the opposite direction dark", "By slice thickness", "Flow direction cannot be shown"], "answer_index": 1, "explanation": "Phase shift is positive or negative depending on direction along the encoding axis, so craniocaudal and caudocranial flow appear bright or dark."}, {"q": "For through-plane quantification of aqueductal flow, how is the slice positioned?", "options": ["Parallel to the aqueduct on a coronal image", "Through the lateral ventricles on an axial image", "Through the foramen magnum on a coronal image", "Perpendicular to the aqueduct, planned on a midsagittal image"], "answer_index": 3, "explanation": "A perpendicular slice crosses the aqueduct cleanly so flow passes straight through the plane, allowing accurate velocity and volume measurement."}]}, {"modality": "MRI", "region": "neck", "region_label": "Neck / Soft Tissue Neck", "exam": "Soft tissue neck (parotids, thyroid, larynx)", "image": {"file": "mri__neck__soft-tissue-neck-parotids-thyroid-larynx.jpg", "caption": "Axial fat-saturated T2-weighted MRI through the parotid glands; the arrow marks a lesion in the right parotid.", "credit": "Birkent H, Karahatay S, Akcam T, Durmaz A, Ongoru O", "license": "CC BY 2.0", "page_url": "https://commons.wikimedia.org/wiki/File:Parotid-gland-tuberculosis.jpg"}, "questions": [{"q": "On this axial fat-saturated T2 image, the arrow marks a right parotid lesion. Which structure running through the parotid divides it into superficial and deep lobes?", "options": ["Facial nerve (CN VII)", "Hypoglossal nerve (CN XII)", "Internal jugular vein", "Thyroid cartilage"], "answer_index": 0, "explanation": "The facial nerve plane separates the superficial and deep lobes, which matters for surgical planning; the retromandibular vein is used as a landmark for it on imaging."}, {"q": "Which coil is preferred for a soft tissue neck MRI?", "options": ["The body coil alone", "A knee coil", "A dedicated head-neck or neck phased-array coil", "A single-channel extremity surface coil"], "answer_index": 2, "explanation": "A neck array places many receive elements close to the anatomy, giving high SNR over the large neck coverage."}, {"q": "Coverage for a general soft tissue neck exam typically extends:", "options": ["From the vertex to the foramen magnum", "From the carina to the diaphragm", "Only through the hyoid bone", "From the skull base to the thoracic inlet"], "answer_index": 3, "explanation": "Neck pathology and nodal spread can occur anywhere from the skull base to the thoracic inlet, so the full span is covered."}]}, {"modality": "MRI", "region": "neck", "region_label": "Neck / Soft Tissue Neck", "exam": "MRA neck (carotids, vertebrals)", "image": {"file": "mri__neck__mra-neck-carotids-vertebrals.jpg", "caption": "Coronal contrast-enhanced MR angiogram (MIP) of the supra-aortic vessels showing the carotid and vertebral arteries in the neck.", "credit": "Germain DP, Orphanet Journal of Rare Diseases 2007, 2:32", "license": "CC BY 2.0", "page_url": "https://commons.wikimedia.org/wiki/File:Angio_MR.jpg"}, "questions": [{"q": "This coronal contrast-enhanced MRA shows the carotid and vertebral arteries. Compared with 2D/3D TOF, a key advantage of CE-MRA is:", "options": ["No need for intravenous access", "Better depiction of venous structures in the arterial phase", "Large coverage from the aortic arch to the skull base in a short acquisition with fewer flow artifacts", "Insensitivity to bolus timing"], "answer_index": 2, "explanation": "CE-MRA relies on T1 shortening by gadolinium rather than inflow, so it covers a large FOV quickly and avoids saturation of slow or in-plane flow."}, {"q": "When the carotid bifurcation is evaluated with TOF instead of CE-MRA, stenosis severity can be overestimated because:", "options": ["Gadolinium pools in the plaque", "Turbulent flow at the stenosis causes intravoxel dephasing and signal loss", "Arterial blood has a long T1", "Fat saturation fails at the bifurcation"], "answer_index": 1, "explanation": "Disturbed, accelerated flow beyond a narrowing dephases spins, creating a flow gap that can exaggerate stenosis on TOF images."}, {"q": "Strong jugular venous enhancement obscures the carotids on a CE-MRA. The most likely cause is:", "options": ["Acquisition started too late after injection", "Acquisition started too early", "Too low a flip angle", "Use of a neck coil"], "answer_index": 0, "explanation": "If the central k-space is acquired after contrast reaches the veins, venous contamination overlaps the arteries; bolus tracking helps prevent this."}]}, {"modality": "MRI", "region": "neck", "region_label": "Neck / Soft Tissue Neck", "exam": "MRV neck", "image": null, "questions": [{"q": "Which condition, a septic thrombophlebitis of the internal jugular vein after pharyngitis, may prompt neck venous imaging?", "options": ["Moyamoya disease", "Sturge-Weber syndrome", "Lemierre syndrome", "Wallenberg syndrome"], "answer_index": 2, "explanation": "Lemierre syndrome is usually caused by Fusobacterium; imaging shows jugular thrombus and perivenous inflammation."}, {"q": "Which normal finding can mimic jugular vein thrombosis on neck MRV?", "options": ["Asymmetric, smaller left internal jugular vein or flow-related signal loss", "A bright superior sagittal sinus", "Symmetric jugular veins", "Fat signal in the parotid glands"], "answer_index": 0, "explanation": "Jugular asymmetry (usually right-dominant) and slow or turbulent flow can cause low signal that should not be mistaken for thrombus."}, {"q": "Contrast-enhanced MRV of the neck is acquired:", "options": ["Only before contrast injection", "During the first-pass arterial phase only", "24 hours after injection", "In a delayed venous phase after the arterial bolus has passed"], "answer_index": 3, "explanation": "Waiting until gadolinium reaches the venous system brightens the veins; subtraction or arterial-phase images help separate arteries."}]}, {"modality": "MRI", "region": "neck", "region_label": "Neck / Soft Tissue Neck", "exam": "Brachial plexus (neck/thoracic inlet)", "image": {"file": "mri__neck__brachial-plexus-neck-thoracic-inlet.jpg", "caption": "High-resolution SSFP MR images of the cervical spine and brachial plexus region in an infant; arrows show a right-sided pseudomeningocele at C8-T1 (illustration panel cropped).", "credit": "Gwendolyn Mack", "license": "CC BY 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Normal_brachial_plexus_and_a_right-sided_pseudomeningocele_at_C8-T1_level.webp"}, "questions": [{"q": "These images show a CSF-filled pseudomeningocele along a lower cervical nerve root (arrows). In brachial plexus trauma, a pseudomeningocele suggests:", "options": ["A normal anatomic variant with no significance", "Nerve root avulsion from the spinal cord", "A schwannoma of the nerve sheath", "Pancoast tumor invasion"], "answer_index": 1, "explanation": "A torn dural root sleeve fills with CSF, so a pseudomeningocele is a strong sign of preganglionic root avulsion."}, {"q": "The brachial plexus is formed by the ventral rami of which spinal nerves?", "options": ["C1 through C4", "C5 through T1", "T1 through T5", "L1 through L4"], "answer_index": 1, "explanation": "The plexus arises from C5-T1, so coverage must include the lower cervical and upper thoracic spine."}, {"q": "Which imaging plane best displays the plexus along its course from the spine toward the axilla?", "options": ["Axial planes through the orbits", "True sagittal through the midline only", "Axial planes through the kidneys", "Oblique coronal planes following the plexus"], "answer_index": 3, "explanation": "The plexus runs obliquely downward and laterally, so oblique coronal slices show roots, trunks and cords in continuity."}]}, {"modality": "MRI", "region": "chest", "region_label": "Chest / Thorax & Heart", "exam": "Cardiac function and viability", "image": {"file": "mri__chest__cardiac-function-and-viability.jpg", "caption": "Cardiac MRI four-chamber late gadolinium enhancement image showing a chronic myocardial infarction.", "credit": "Doregan", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:4CH_IR_infarct.jpg"}, "questions": [{"q": "This four-chamber LGE image comes from a function-and-viability exam. How is LV ejection fraction calculated from the cine short-axis stack?", "options": ["(EDV - ESV) / EDV, from contours traced at end-diastole and end-systole", "ESV / EDV", "EDV - ESV only", "Heart rate x stroke volume"], "answer_index": 0, "explanation": "Volumes from the short-axis stack give stroke volume (EDV - ESV), which divided by EDV is the ejection fraction."}, {"q": "What is the purpose of the TI scout (Look-Locker) sequence before LGE imaging?", "options": ["To calculate ejection fraction", "To set the VENC", "To choose an inversion time that nulls normal myocardium", "To locate the coronary arteries"], "answer_index": 2, "explanation": "The correct TI makes normal myocardium black so enhancing scar appears bright; the optimal TI lengthens as gadolinium washes out."}, {"q": "In viability assessment, a segment with LGE extending through more than 50% of the wall thickness is:", "options": ["Very likely to recover fully", "Normal myocardium", "Diagnostic of pericarditis", "Unlikely to recover function after revascularization"], "answer_index": 3, "explanation": "The transmural extent of scar predicts recovery: little or no LGE suggests viable tissue, while greater than 50% transmurality predicts poor recovery."}]}, {"modality": "MRI", "region": "chest", "region_label": "Chest / Thorax & Heart", "exam": "Chest (noncardiac) / mediastinum", "image": {"file": "mri__chest__chest-noncardiac-mediastinum.jpg", "caption": "Coronal MRI of the chest showing the mediastinum and hila with low-signal lungs (title text cropped).", "credit": "Golshani7", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Conventional_MRI_of_the_chest.jpg"}, "questions": [{"q": "On this coronal chest MR image the lungs are dark while the mediastinum is bright. Why does lung parenchyma have low signal?", "options": ["The lungs absorb RF energy", "Lung tissue has a very long T1 and T2", "Low proton density and rapid T2* decay from many air-tissue interfaces", "Gadolinium is excluded from the lungs"], "answer_index": 2, "explanation": "Lung contains little tissue, and susceptibility differences at countless air-tissue boundaries cause fast dephasing, so it is nearly signal-free."}, {"q": "Which technique reduces cardiac pulsation artifact during mediastinal MRI?", "options": ["Increasing the slice gap", "ECG gating or triggering", "Removing fat saturation", "Using a smaller matrix in the slice direction"], "answer_index": 1, "explanation": "Synchronizing acquisition to the cardiac cycle keeps the heart and great vessels in the same position, reducing ghosting across the mediastinum."}, {"q": "Chemical shift (in-phase/opposed-phase) imaging of an anterior mediastinal mass helps distinguish:", "options": ["Normal or hyperplastic thymus (signal drop) from thymoma or lymphoma", "Calcified from noncalcified lymph nodes", "Arterial from venous structures", "Pleural from pericardial fluid"], "answer_index": 0, "explanation": "Thymic hyperplasia contains microscopic fat that loses signal on opposed-phase images, while neoplasms usually do not."}]}, {"modality": "MRI", "region": "chest", "region_label": "Chest / Thorax & Heart", "exam": "Breast", "image": {"file": "mri__chest__breast.jpg", "caption": "Contrast-enhanced MRI of a single breast showing a markedly enhancing cancer (bright area).", "credit": "Unknown photographer (National Cancer Institute Visuals Online)", "license": "Public domain", "page_url": "https://commons.wikimedia.org/wiki/File:Mri_of_breast_cancer.jpg"}, "questions": [{"q": "This contrast-enhanced breast image shows a brightly enhancing cancer. The first post-contrast dynamic acquisition should be centered within about how long after injection?", "options": ["10 minutes", "30 minutes", "1-2 minutes", "4 hours"], "answer_index": 2, "explanation": "Cancers typically enhance most in the first 1-2 minutes, so early-phase timing is critical for detection and kinetic analysis."}, {"q": "Why are subtraction images produced in breast MRI?", "options": ["To remove pre-contrast signal so enhancing tissue stands out", "To measure breast density in g/cm3", "To eliminate the need for fat suppression in all cases", "To correct for coil sensitivity"], "answer_index": 0, "explanation": "Subtracting pre-contrast from post-contrast images leaves mainly the enhancement, highlighting lesions against fat and parenchyma."}, {"q": "Which gadolinium dose is standard for diagnostic breast MRI?", "options": ["0.5 mmol/kg", "1.0 mmol/kg", "0.01 mmol/kg", "0.1 mmol/kg"], "answer_index": 3, "explanation": "A standard single dose of 0.1 mmol/kg followed by a saline flush is used for breast DCE-MRI."}]}, {"modality": "MRI", "region": "chest", "region_label": "Chest / Thorax & Heart", "exam": "Vascular thorax (thoracic aorta MRA)", "image": {"file": "mri__chest__vascular-thorax-thoracic-aorta-mra.jpg", "caption": "Oblique sagittal MR image of the thoracic aorta showing an aortic dissection (labels mark the true/false lumen and flap region).", "credit": "Dr. Lars Grenacher (www.grenacher.de)", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:AoDiss_MRT.jpg"}, "questions": [{"q": "This oblique sagittal image displays the ascending aorta, arch and descending aorta with a dissection. What is this imaging plane commonly called?", "options": ["The four-chamber view", "The 'candy cane' view", "The short-axis view", "The two-chamber view"], "answer_index": 1, "explanation": "An oblique sagittal plane through the ascending and descending aorta shows the whole arch in one image, like a candy cane."}, {"q": "Which noncontrast technique can provide bright-blood 3D images of the thoracic aorta for a patient who cannot receive gadolinium?", "options": ["Black-blood single-shot EPI diffusion", "ECG-gated, navigator-triggered 3D balanced SSFP", "Spectral fat-saturated T1 spin echo", "STIR"], "answer_index": 1, "explanation": "Balanced SSFP gives intrinsically bright blood; gating and navigators reduce cardiac and respiratory motion."}, {"q": "Why is ECG gating important when evaluating the aortic root?", "options": ["It increases gadolinium relaxivity", "It suppresses fat signal", "It shortens T1 of blood", "It removes pulsation blurring that can mimic a dissection flap"], "answer_index": 3, "explanation": "The root moves substantially during the cardiac cycle; ungated images can show motion artifacts that look like a flap."}]}, {"modality": "MRI", "region": "chest", "region_label": "Chest / Thorax & Heart", "exam": "Brachial plexus", "image": {"file": "mri__chest__brachial-plexus.jpg", "caption": "Deterministic diffusion tensor tractography of the adult brachial plexus reconstructed from MR diffusion data.", "credit": "Ryckiewade", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Deterministic_Tractography_of_the_Adult_Brachial_Plexus_using_Diffusion_Tensor_Imaging.gif"}, "questions": [{"q": "This 3D image of the brachial plexus nerve fibers was reconstructed from which MR acquisition?", "options": ["Diffusion tensor imaging (DTI)", "Time-of-flight MRA", "Phase-contrast flow imaging", "In-phase/opposed-phase GRE"], "answer_index": 0, "explanation": "Tractography follows the preferred direction of water diffusion along nerve fibers, which DTI measures with multiple diffusion directions."}, {"q": "Brachial plexus MRI coverage should extend:", "options": ["From the vertex to C2 only", "From the carina to the diaphragm", "From the cervical spine nerve roots laterally through the axilla", "From the shoulder joint to the elbow only"], "answer_index": 2, "explanation": "Lesions can occur from the root origins at the cord to the cords and branches near the axilla, so the full course is covered."}, {"q": "A superior sulcus (Pancoast) tumor most often involves which part of the brachial plexus first?", "options": ["Upper trunk (C5-C6)", "Musculocutaneous nerve", "Suprascapular nerve", "Lower trunk (C8-T1)"], "answer_index": 3, "explanation": "Apical lung tumors sit next to the lower trunk and T1 root, so ulnar-sided hand symptoms are typical; MRI shows plexus and chest wall invasion."}]}, {"modality": "MRI", "region": "abdomen", "region_label": "Abdomen", "exam": "Liver", "image": {"file": "mri__abdomen__liver.jpg", "caption": "Multiecho in-phase and out-of-phase MR images of a healthy liver (top) and a liver with severe steatosis (bottom).", "credit": "SpinDfazor", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:MRI_Liversteatosis.jpg"}, "questions": [{"q": "In this multiecho series, the steatotic liver loses signal on the out-of-phase echo. Why?", "options": ["Iron deposition shortens T2*", "Gadolinium is excluded from fatty liver", "Fat and water signals within the same voxel cancel when they are out of phase", "Fat has a longer T2 than water"], "answer_index": 2, "explanation": "At opposed-phase TEs, fat and water vectors point in opposite directions, so voxels containing both lose signal."}, {"q": "Why is diffusion-weighted imaging included in a liver MRI protocol?", "options": ["It replaces all post-contrast imaging", "It improves detection of small lesions such as metastases, which often restrict diffusion", "It quantifies liver iron", "It shows the bile ducts in 3D"], "answer_index": 1, "explanation": "Background liver signal is suppressed at higher b-values, so small cellular lesions stand out."}, {"q": "Gadolinium is injected early in a liver protocol, and T2-weighted and DWI images are acquired before the delayed phases. Why does this work?", "options": ["Gadolinium at these concentrations has little effect on T2-weighted and DWI contrast", "Gadolinium makes T2 images brighter", "DWI requires contrast", "It lowers SAR"], "answer_index": 0, "explanation": "Post-contrast T2 and DWI remain diagnostic, so the waiting time before delayed or hepatobiliary phases can be used efficiently."}]}, {"modality": "MRI", "region": "abdomen", "region_label": "Abdomen", "exam": "Pancreas", "image": {"file": "mri__abdomen__pancreas.jpg", "caption": "Axial T2- and T1-weighted MRI of the upper abdomen showing fatty replacement (lipomatosis) of the pancreas in cystic fibrosis.", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Pankreaslipomatose_bei_Mukoviszidose_45jm_-_MRT_T2_und_T1_axial_-_001.jpg"}, "questions": [{"q": "These axial images show a pancreas replaced by fat. On fat-suppressed T1 images, a normal pancreas is typically:", "options": ["Darker than the spleen and muscle", "Signal-free", "One of the brightest organs in the abdomen", "Identical to CSF"], "answer_index": 2, "explanation": "Protein-rich acinar tissue gives normal pancreas high T1 signal; loss of that signal suggests fibrosis, chronic pancreatitis or replacement."}, {"q": "Pancreatic adenocarcinoma is usually most conspicuous on MRI as:", "options": ["A hypoenhancing mass on the pancreatic (late arterial) phase", "A hyperenhancing mass on arterial images", "A T1-bright mass on fat-suppressed images", "A lesion visible only on delayed phase"], "answer_index": 0, "explanation": "Normal pancreas enhances strongly in the late arterial phase, while desmoplastic adenocarcinoma enhances poorly and appears darker."}, {"q": "Which pancreatic cystic lesion communicates with the pancreatic duct, a feature well shown on MRCP?", "options": ["Serous cystadenoma", "Simple renal cyst", "Splenic cyst", "Intraductal papillary mucinous neoplasm (IPMN)"], "answer_index": 3, "explanation": "IPMNs arise from the ductal epithelium; showing communication with the main or branch ducts on MRCP supports the diagnosis."}]}, {"modality": "MRI", "region": "abdomen", "region_label": "Abdomen", "exam": "Adrenals", "image": {"file": "mri__abdomen__adrenals.jpg", "caption": "Axial T1-weighted in-phase (top) and opposed-phase (bottom) MRI showing a right adrenal adenoma that loses signal on opposed-phase.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Adenom_der_rechten_Nebenniere_-_in_phase_out_of_phase_55W_-_MR_T1_ip_op_axial_-_001.jpg"}, "questions": [{"q": "This in-phase/opposed-phase image pair is acquired with which sequence?", "options": ["T2-weighted fast spin echo", "T1-weighted dual-echo gradient echo (chemical shift imaging)", "Diffusion-weighted EPI", "STIR"], "answer_index": 1, "explanation": "Gradient echo has no refocusing pulse, so choosing TEs where fat and water are in or out of phase produces the chemical shift pair."}, {"q": "When judging adrenal signal drop on chemical shift imaging, which organ is the preferred internal reference?", "options": ["Liver", "Spleen", "Subcutaneous fat", "Kidney cortex"], "answer_index": 1, "explanation": "The liver may itself be fatty or iron-loaded, so the spleen is usually the more reliable reference."}, {"q": "A pheochromocytoma classically appears on T2-weighted images as:", "options": ["Profoundly dark", "Isointense to muscle", "Signal-free", "Markedly hyperintense ('light bulb' bright)"], "answer_index": 3, "explanation": "Many pheochromocytomas are very bright on T2, though appearance varies; biochemical tests confirm the diagnosis."}]}, {"modality": "MRI", "region": "abdomen", "region_label": "Abdomen", "exam": "Kidneys", "image": {"file": "mri__abdomen__kidneys.jpg", "caption": "Axial T2-weighted MRI of the abdomen at the level of the kidneys in a patient with a horseshoe kidney.", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Hufeisenniere_01_-_MRT_-_T2_axial_-_013.jpg"}, "questions": [{"q": "This axial T2 image shows both kidneys low in the abdomen with renal tissue near the midline. Fusion of the lower poles across the midline in front of the aorta is called:", "options": ["Horseshoe kidney", "Crossed ectopia", "Duplex collecting system", "Polycystic kidney disease"], "answer_index": 0, "explanation": "In a horseshoe kidney the lower poles are joined by an isthmus anterior to the aorta and IVC, usually held low by the inferior mesenteric artery."}, {"q": "On renal MRI, which finding indicates a solid or complex mass rather than a simple cyst?", "options": ["Uniform high T2 signal", "No enhancement", "Enhancement on subtracted post-contrast images", "Thin imperceptible wall"], "answer_index": 2, "explanation": "Subtraction removes intrinsic T1 brightness (blood, protein), so true enhancement indicates vascularized tissue."}, {"q": "A renal lesion is homogeneously very bright on T2, has an imperceptible wall and shows no enhancement. It is most consistent with:", "options": ["Renal cell carcinoma", "Angiomyolipoma", "Renal abscess", "A simple (Bosniak I) cyst"], "answer_index": 3, "explanation": "Simple cysts contain fluid with long T2, have hairline walls and do not enhance."}]}, {"modality": "MRI", "region": "abdomen", "region_label": "Abdomen", "exam": "MRCP", "image": {"file": "mri__abdomen__mrcp.jpg", "caption": "Normal MRCP maximum intensity projection showing the gallbladder, bile ducts and pancreatic duct.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:MRCP_Normalbefund_66M_-_MR_-_001.jpg"}, "questions": [{"q": "This MRCP is displayed as a thick-slab projection. What is a key limitation of thick-slab or MIP MRCP images?", "options": ["Ducts always look narrower than they are", "They cannot show the gallbladder", "Small stones can be hidden by surrounding bright bile, so thin source images must be reviewed", "They require IV contrast"], "answer_index": 2, "explanation": "Projection images overlap bright fluid; a small dark stone can be masked, so source slices are checked."}, {"q": "On MRCP, a common bile duct stone typically appears as:", "options": ["A bright focus brighter than bile", "A dark filling defect within bright bile", "A region of fat signal", "A flow void in the portal vein"], "answer_index": 1, "explanation": "Stones contain few mobile protons and appear as signal voids surrounded by high-signal fluid."}, {"q": "On MRCP, pancreas divisum is diagnosed when:", "options": ["The dominant dorsal pancreatic duct drains into the minor papilla without joining the ventral duct", "The common bile duct is dilated above 6 mm", "The gallbladder is absent", "The pancreatic duct is visible at all"], "answer_index": 0, "explanation": "In divisum the dorsal and ventral ducts fail to fuse, so most pancreatic drainage goes through the minor papilla."}]}, {"modality": "MRI", "region": "abdomen", "region_label": "Abdomen", "exam": "MR enterography", "image": {"file": "mri__abdomen__mr-enterography.jpg", "caption": "Axial post-contrast fat-suppressed T1-weighted MRI showing a thick-walled, enhancing terminal ileum in long-standing Crohn disease (CT row cropped).", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Ileitis_terminalis_bei_langjaehrigem_Morbus_Crohn_63W_-_CT_und_MRT_-_001.jpg"}, "questions": [{"q": "These post-contrast fat-suppressed T1 images show a thickened, enhancing terminal ileum. Which plane is primary in MR enterography for displaying long bowel segments?", "options": ["Sagittal", "Oblique axial through the liver", "Coronal", "Axial only, no other plane"], "answer_index": 2, "explanation": "Coronal images show long lengths of small bowel and the mesentery on fewer slices; axial images are added for confirmation."}, {"q": "Why is balanced SSFP (TrueFISP/FIESTA) useful in MR enterography?", "options": ["It provides fast, motion-resistant bright-fluid images of the bowel wall and mesentery", "It is the only sequence that shows enhancement", "It suppresses all fluid signal", "It requires no oral contrast"], "answer_index": 0, "explanation": "Balanced SSFP is quick and tolerant of motion, showing bowel wall, fistulas and engorged mesenteric vessels (comb sign)."}, {"q": "Which combination suggests active inflammation on MR enterography?", "options": ["Fatty submucosal deposition with no enhancement", "A thin wall with no enhancement", "Bright intraluminal fluid only", "Wall thickening, mural hyperenhancement, T2 wall edema and restricted diffusion"], "answer_index": 3, "explanation": "Active Crohn disease shows thickened, hyperenhancing, edematous bowel wall, often with the comb sign and restricted diffusion."}]}, {"modality": "MRI", "region": "abdomen", "region_label": "Abdomen", "exam": "Vascular abdomen (MRA/MRV)", "image": {"file": "mri__abdomen__vascular-abdomen-mra-mrv.jpg", "caption": "Color MIP of abdominal contrast-enhanced MRA showing the aorta and its branches (arterial phase in red).", "credit": "Nevit Dilmen (talk)", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Abdominal_MRA_Color_MIP_case_01_12.jpg"}, "questions": [{"q": "This color MIP from an abdominal CE-MRA displays the aorta and its branches. In atherosclerotic renal artery stenosis, which segment is usually involved?", "options": ["The mid-to-distal renal artery with a 'string of beads'", "The ostium and proximal renal artery", "The renal veins", "The intrarenal arcuate arteries only"], "answer_index": 1, "explanation": "Atherosclerosis typically narrows the ostium and proximal segment, while fibromuscular dysplasia affects the mid and distal artery."}, {"q": "On abdominal MRA, an infrarenal aortic diameter of at least what size defines an abdominal aortic aneurysm?", "options": ["1 cm", "3 cm", "1.5 cm", "8 cm"], "answer_index": 1, "explanation": "An infrarenal aortic diameter of 3 cm or more is the usual definition of AAA; MRA also shows its relation to the renal arteries."}, {"q": "Which noncontrast technique is commonly used to image the renal arteries?", "options": ["T1 spin echo without gating", "Diffusion-weighted EPI", "In-phase/opposed-phase GRE", "Inflow-sensitive balanced SSFP with a slab-selective inversion pulse"], "answer_index": 3, "explanation": "An inversion pulse suppresses background and venous signal while fresh arterial blood flows into the slab and appears bright on SSFP."}]}, {"modality": "MRI", "region": "pelvis", "region_label": "Pelvis", "exam": "Female pelvis (uterus, ovaries)", "image": {"file": "mri__pelvis__female-pelvis-uterus-ovaries.jpg", "caption": "Sagittal T2-weighted MRI of the female pelvis showing a markedly anteverted uterus above the bladder.", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Female_pelvis_with_extreme_anteversion_of_the_uterus.png"}, "questions": [{"q": "Which sequence best demonstrates the zonal anatomy of the uterus (endometrium, junctional zone, myometrium)?", "options": ["T1-weighted spin echo", "Time-of-flight GRE", "T2-weighted FSE", "Opposed-phase GRE"], "answer_index": 2, "explanation": "On T2W images the endometrium is bright, the junctional zone dark, and the outer myometrium intermediate; T1W shows little zonal contrast."}, {"q": "On this sagittal T2 image the uterine body is tipped steeply forward over the bladder. How should the dedicated small-FOV uterine planes be prescribed?", "options": ["Oblique, along the long and short axes of the uterus as seen on the sagittal T2", "True axial to the table, regardless of uterine position", "Parallel to the sacrum", "Perpendicular to the femoral necks"], "answer_index": 0, "explanation": "Because uterine position varies widely, axial and coronal obliques are angled to the uterus itself so the junctional zone and cavity are shown without partial volume."}, {"q": "A bright adnexal mass on T1 stays bright on fat-suppressed T1. Which lesion does this favor?", "options": ["Mature cystic teratoma (dermoid)", "Simple follicular cyst", "Endometrioma", "Serous cystadenoma"], "answer_index": 2, "explanation": "Blood products in an endometrioma remain bright with fat suppression, whereas the fat in a dermoid loses signal."}]}, {"modality": "MRI", "region": "pelvis", "region_label": "Pelvis", "exam": "Male pelvis / prostate (multiparametric)", "image": {"file": "mri__pelvis__male-pelvis-prostate-multiparametric.jpg", "caption": "Axial T2-weighted prostate MRI with a hydrogel spacer separating the prostate from the rectum.", "credit": "Pkcemail", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Prostate_spacer.jpg"}, "questions": [{"q": "In prostate multiparametric MRI, what b-value is recommended for the high-b DWI series?", "options": ["0 s/mm² only", "About 100 s/mm²", "About 500 s/mm²", "At least 1,400 s/mm²"], "answer_index": 3, "explanation": "High b-values (≥1,400 s/mm²) suppress normal tissue so that clinically significant cancer stands out as bright."}, {"q": "Per PI-RADS v2.1 technical recommendations, what slice thickness is advised for axial T2-weighted prostate images?", "options": ["About 3 mm with no gap", "8 mm with a 2 mm gap", "10 mm contiguous", "Slice thickness is not specified"], "answer_index": 0, "explanation": "Thin 3 mm contiguous T2W slices with an in-plane resolution of about 0.4 x 0.7 mm or better are recommended for prostate anatomy and lesion detection."}, {"q": "This axial T2 image shows the prostate with the rectum just behind it. Why are patients asked to empty the rectum before a prostate MRI?", "options": ["Rectal gas causes susceptibility distortion on the EPI diffusion images", "Stool increases SAR", "A full rectum blocks gadolinium from reaching the prostate", "It shortens the T1 of the peripheral zone"], "answer_index": 0, "explanation": "Air in the rectum next to the gland distorts echo-planar DWI; evacuation (sometimes a small enema) reduces this artifact."}]}, {"modality": "MRI", "region": "pelvis", "region_label": "Pelvis", "exam": "Bladder", "image": {"file": "mri__pelvis__bladder.jpg", "caption": "Sagittal T2-weighted pelvic MRI: urinary bladder (red arrow), suspected urachal cyst (green), ovarian cyst (yellow).", "credit": "Stefanopol IA, Miulescu M, Baroiu L, et al.", "license": "CC BY 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Pelvic_MRI_image_Sagittal_T2-weighted_yellow_arrow_left_ovarian_cyst%3B_green_arrow_supposed_urachal_cyst%3B_red_arrow_urinary_bladder.png"}, "questions": [{"q": "For a bladder cancer staging MRI, what bladder state is preferred?", "options": ["Completely empty, with a Foley catheter", "Moderately to well distended, with the patient voiding 1–2 hours before", "Overdistended with 1 L of oral water drunk just before scanning", "State of filling does not matter"], "answer_index": 1, "explanation": "Adequate distension lets the wall layers be judged; an empty bladder mimics wall thickening, while overdistension causes discomfort and motion."}, {"q": "The Vesical Imaging-RADS (VI-RADS) protocol for bladder cancer is based on which combination of sequences?", "options": ["T1W in- and opposed-phase only", "Time-of-flight MRA and T2*", "MR urography alone", "Multiplanar T2W, DWI, and dynamic contrast-enhanced imaging"], "answer_index": 3, "explanation": "VI-RADS scores muscle invasion using high-resolution T2W, DWI, and DCE, with DWI the dominant sequence."}, {"q": "On this sagittal T2 image, a small cyst (green arrow) lies above the anterior dome of the bladder. A urachal remnant runs from the bladder dome toward which structure?", "options": ["The umbilicus", "The pubic symphysis", "The sacral promontory", "The inguinal canal"], "answer_index": 0, "explanation": "The urachus connects the bladder dome to the umbilicus in the midline; remnants appear as cysts or tracts along that course."}]}, {"modality": "MRI", "region": "pelvis", "region_label": "Pelvis", "exam": "Rectum", "image": null, "questions": [{"q": "Why is an antiperistaltic agent (e.g., glucagon or hyoscine butylbromide) often given for rectal MRI?", "options": ["To distend the rectum", "To decrease SAR", "To reduce bowel motion artifact", "To improve gadolinium enhancement of the tumor"], "answer_index": 2, "explanation": "Slowing peristalsis reduces ghosting and blurring on the long high-resolution T2 sequences."}, {"q": "On rectal cancer staging MRI, tumor lies 1 mm or less from the mesorectal fascia. What does this indicate?", "options": ["A normal finding", "A threatened or involved circumferential resection margin", "Lymph node metastasis", "Peritoneal reflection involvement only"], "answer_index": 1, "explanation": "Tumor within 1 mm of the mesorectal fascia predicts a positive surgical margin and usually leads to neoadjuvant therapy."}, {"q": "On a perianal fistula MRI, which sequence best shows an active fistula tract?", "options": ["Fat-suppressed T2 or STIR, where the fluid-filled tract is bright", "Non-fat-suppressed T1, where the tract is bright", "Time-of-flight GRE", "In-phase GRE"], "answer_index": 0, "explanation": "Fluid and inflammation in an active tract are bright against suppressed fat on STIR/fat-suppressed T2; post-contrast T1 FS is a helpful addition."}]}, {"modality": "MRI", "region": "pelvis", "region_label": "Pelvis", "exam": "Vascular pelvis (MRA/MRV)", "image": {"file": "mri__pelvis__vascular-pelvis-mra-mrv.jpg", "caption": "Coronal contrast-enhanced MR angiography MIP showing the aorta, renal arteries, and iliac bifurcation.", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Hufeisenniere_01_-_MRT_-_MR_CE-Angiographie_-_MIP_-_008.jpg"}, "questions": [{"q": "This coronal contrast-enhanced MRA MIP shows the abdominal aorta dividing into the common iliac arteries. At about what vertebral level does the aorta normally bifurcate?", "options": ["T12", "L4", "L1", "S2"], "answer_index": 1, "explanation": "The aortic bifurcation usually lies at the L4 level, so a pelvic MRA field of view must start above it."}, {"q": "Pelvic MRA is sometimes done before uterine fibroid embolization. From which artery does the uterine artery usually arise?", "options": ["External iliac artery", "Inferior mesenteric artery", "Anterior division of the internal iliac artery", "Common femoral artery"], "answer_index": 2, "explanation": "The uterine artery is typically a branch of the anterior division of the internal iliac (hypogastric) artery, the vessel catheterized for embolization."}, {"q": "May-Thurner syndrome, a cause of left leg swelling evaluated with pelvic MRV, is compression of which vessel?", "options": ["Right common iliac vein by the left common iliac artery", "Left renal vein by the superior mesenteric artery", "Inferior vena cava by the liver", "Left common iliac vein by the right common iliac artery"], "answer_index": 3, "explanation": "The right common iliac artery crosses over and compresses the left common iliac vein against the spine, predisposing to left-sided DVT."}]}, {"modality": "MRI", "region": "pelvis", "region_label": "Pelvis", "exam": "Bony pelvis and hips", "image": {"file": "mri__pelvis__bony-pelvis-and-hips.jpg", "caption": "Coronal STIR of the bony pelvis and both hips (transient osteoporosis of the hip).", "credit": "Ruiz Santiago F, et al.", "license": "CC BY 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:STIR_MRI_of_transient_osteoporosis.jpg"}, "questions": [{"q": "This coronal STIR image covers the whole bony pelvis and both hips. Why is STIR often preferred over spectral fat saturation for this large FOV?", "options": ["STIR gives more uniform fat suppression over a large, inhomogeneous field", "STIR has the highest SNR of any sequence", "STIR is required after gadolinium", "STIR has no specific absorption rate"], "answer_index": 0, "explanation": "STIR suppresses fat by inversion time rather than frequency, so it is not degraded by B0 inhomogeneity across a wide FOV."}, {"q": "An elderly patient has hip pain after a fall and normal radiographs. Which short protocol is most sensitive for an occult fracture?", "options": ["Axial GRE only", "Sagittal PD only", "Coronal T1 and coronal STIR of the pelvis", "MR angiography of the pelvis"], "answer_index": 2, "explanation": "A dark fracture line on T1 with bright marrow edema on STIR covers the femoral necks, pubic rami, and sacrum in a few minutes."}, {"q": "On a T1-weighted pelvis image, when does adult bone marrow suggest an infiltrative process?", "options": ["When it is brighter than subcutaneous fat", "When it is darker than adjacent muscle or normal disc", "When it is the same signal as yellow marrow", "When it shows chemical shift artifact"], "answer_index": 1, "explanation": "Normal adult marrow contains fat and is brighter than muscle on T1; marrow darker than muscle or disc suggests replacement by tumor or other infiltration."}]}, {"modality": "MRI", "region": "spine", "region_label": "Spine", "exam": "Cervical spine", "image": {"file": "mri__spine__cervical-spine.jpg", "caption": "Sagittal T2-weighted cervical spine MRI with a C5–C6 disc herniation.", "credit": "Brain&Spineman9", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:HWS_Vorfall_C56.png"}, "questions": [{"q": "This sagittal T2 cervical image shows a disc herniation at the most common cervical level. Which level is that?", "options": ["C2–C3", "C3–C4", "C5–C6", "C7–T1"], "answer_index": 2, "explanation": "C5–C6 (followed by C6–C7) carries the most motion and is the most frequent site of cervical disc herniation."}, {"q": "Axial cervical images for the neural foramina are often acquired as a T2* gradient-echo sequence (e.g., MEDIC/MERGE). What is the main advantage?", "options": ["Bright CSF with little flow artifact, giving good cord and foraminal contrast with thin slices", "Best detection of marrow edema", "Lowest susceptibility to metal", "No need for a neck coil"], "answer_index": 0, "explanation": "GRE axials give a myelographic effect with less CSF-pulsation artifact than spin echo and allow thin contiguous slices."}, {"q": "Swallowing motion degrades sagittal cervical spine images. Which measure most directly reduces it?", "options": ["Increase the slice gap", "Switch to the body coil", "Lengthen the TR", "Place a saturation band over the pharynx and anterior neck and ask the patient not to swallow during scans"], "answer_index": 3, "explanation": "An anterior saturation band nulls signal from the moving pharynx, and clear instructions cut down the motion itself."}]}, {"modality": "MRI", "region": "spine", "region_label": "Spine", "exam": "Thoracic spine", "image": {"file": "mri__spine__thoracic-spine.jpg", "caption": "Thoracic spine meningioma: sagittal contrast-enhanced T1 (left) with a second view (right).", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Meningeom_im_Spinalkanal_MRT.jpg"}, "questions": [{"q": "Which sequence best shows bone-marrow edema from an acute thoracic vertebral compression fracture?", "options": ["Sagittal T1 without fat suppression", "Sagittal STIR", "Axial gradient echo T2*", "3D time-of-flight"], "answer_index": 1, "explanation": "STIR suppresses marrow fat so edema in an acute fracture is bright; T1 shows it as dark but with less conspicuity."}, {"q": "This sagittal post-contrast T1 image shows an avidly enhancing mass in the thoracic canal. If such a mass is intradural and extramedullary, compresses the cord, and has a dural tail in a middle-aged woman, what is the most likely diagnosis?", "options": ["Ependymoma", "Multiple sclerosis plaque", "Disc extrusion", "Meningioma"], "answer_index": 3, "explanation": "Thoracic meningiomas, most common in middle-aged women, are intradural extramedullary, enhance avidly, and often show a dural tail."}, {"q": "Cardiac and respiratory motion ghosts overlie the cord on sagittal thoracic spine images. Which step most directly helps?", "options": ["Place a saturation band anterior to the spine over the heart and mediastinum", "Increase the slice thickness to 8 mm", "Turn off the spine coil elements", "Remove the no-phase-wrap option"], "answer_index": 0, "explanation": "An anterior saturation band nulls signal from the moving heart and chest so its ghosts no longer project over the canal."}]}, {"modality": "MRI", "region": "spine", "region_label": "Spine", "exam": "Lumbar spine", "image": {"file": "mri__spine__lumbar-spine.jpg", "caption": "Sagittal T2 FRFSE lumbar spine MRI with multilevel disc degeneration (1.5 T).", "credit": "Ptrump16", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:SAGITTAL-FRFSE-T2_MRI.jpg"}, "questions": [{"q": "The iliac crests, often used as an external landmark for lumbar spine positioning, correspond to approximately which level?", "options": ["T10–T11", "L1–L2", "S2–S3", "L4–L5"], "answer_index": 3, "explanation": "The intercristal line usually crosses the L4 body or L4–L5 interspace, a common reference for centering the lumbar spine."}, {"q": "On this sagittal T2 lumbar image, why do the lower degenerated discs look darker than the healthy upper discs?", "options": ["They contain gadolinium", "They have lost water (desiccation), lowering T2 signal", "They contain fat", "Magic angle artifact"], "answer_index": 1, "explanation": "A healthy nucleus pulposus is water-rich and bright on T2; degeneration dehydrates the disc so it turns dark."}, {"q": "Why is a sponge or bolster placed under the knees for a lumbar spine MRI?", "options": ["To raise the spine to isocenter", "To reduce SAR", "To flatten the lumbar lordosis and help the patient stay still", "To prevent nerve stimulation"], "answer_index": 2, "explanation": "Flexing the knees eases back strain and brings the lumbar spine closer to the coil, improving comfort and reducing motion."}]}, {"modality": "MRI", "region": "spine", "region_label": "Spine", "exam": "Total spine", "image": {"file": "mri__spine__total-spine.jpg", "caption": "Whole-spine sagittal STIR images showing inflammatory vertebral corner lesions in ankylosing spondylitis.", "credit": "Weber U, et al.", "license": "CC BY 2.0", "page_url": "https://commons.wikimedia.org/wiki/File:12891_2006_Article_297_Fig3_HTML.jpg"}, "questions": [{"q": "When labeling vertebral levels on a total spine exam, what is the most reliable method?", "options": ["Count upward from the lowest rib", "Count from C2 on a large-FOV sagittal localizer that includes the cervical spine", "Assume the conus ends at L1–L2", "Count downward from the aortic arch"], "answer_index": 1, "explanation": "Thoracic levels are easily mislabeled; counting from C2 on a cervicothoracic localizer avoids wrong-level reporting."}, {"q": "How is a sagittal total-spine image usually produced on a standard bore scanner?", "options": ["A single 100 cm FOV acquisition", "With the body coil only", "In two or three overlapping table stations that are then composed (stitched) into one image", "By reformatting an axial 3D dataset"], "answer_index": 2, "explanation": "Gradient linearity limits the usable FOV, so cervical, thoracic, and lumbar stations with overlap are acquired and joined."}, {"q": "This whole-spine sagittal STIR in a young man with inflammatory back pain shows bright foci at the corners of several vertebral bodies. These corner lesions most suggest:", "options": ["Ankylosing spondylitis", "Osteoporotic fractures", "Metastatic disease", "Schmorl nodes"], "answer_index": 0, "explanation": "Inflammatory corner lesions (Romanus lesions) at vertebral margins on STIR are typical of axial spondyloarthritis such as ankylosing spondylitis."}]}, {"modality": "MRI", "region": "spine", "region_label": "Spine", "exam": "Sacrum/coccyx", "image": {"file": "mri__spine__sacrum-coccyx.jpg", "caption": "Sagittal MRI of the lumbosacral spine showing sacral perineural (Tarlov) cysts.", "credit": "Malisan.mrosa", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Tarlov_Cysts-Sagittal_MRI.JPG"}, "questions": [{"q": "This sagittal image shows several CSF-signal cysts along the sacral nerve roots. What are they?", "options": ["Tarlov (perineural) cysts", "Sacral chordoma", "Hemangiomas", "Synovial cysts"], "answer_index": 0, "explanation": "Tarlov cysts are CSF-filled dilations of the nerve root sheaths, bright on T2 and usually found incidentally in the sacral canal."}, {"q": "An elderly osteoporotic patient has low back pain. On coronal STIR, bright edema bands run vertically through both sacral alae with a horizontal band across the body. This suggests:", "options": ["Sacroiliitis", "Sacral insufficiency fracture", "Tarlov cysts", "Chordoma"], "answer_index": 1, "explanation": "The H-shaped (“Honda sign”) edema pattern is classic for bilateral sacral insufficiency fractures."}, {"q": "A sacrococcygeal chordoma typically has what appearance on T2-weighted images?", "options": ["Very low signal like cortical bone", "Signal identical to fat", "Signal void from calcium only", "A lobulated, very bright midline mass"], "answer_index": 3, "explanation": "Chordomas are midline lobulated tumors with very high T2 signal from their myxoid matrix, often with low-signal septa."}]}, {"modality": "MRI", "region": "spine", "region_label": "Spine", "exam": "SI joints", "image": {"file": "mri__spine__si-joints.jpg", "caption": "Semi-coronal T1-weighted images of the sacroiliac joints before (a) and after (b) contrast in psoriatic sacroiliitis.", "credit": "McQueen F, Lassere M, Østergaard M", "license": "CC BY 2.0", "page_url": "https://commons.wikimedia.org/wiki/File:Sacroiliitis_MRI_ar1934-5.gif"}, "questions": [{"q": "In active sacroiliitis, which STIR finding is the key MRI criterion for axial spondyloarthritis?", "options": ["Fat metaplasia in the joint", "Joint ankylosis", "Subchondral bone marrow edema (osteitis)", "Air in the joint"], "answer_index": 2, "explanation": "Periarticular marrow edema on STIR or post-contrast T1 FS defines active sacroiliitis in the ASAS criteria."}, {"q": "Which sequence is best for chronic structural changes of sacroiliitis such as erosions, sclerosis, and fat metaplasia?", "options": ["T1-weighted spin echo", "Diffusion-weighted imaging", "Time-of-flight GRE", "MR spectroscopy"], "answer_index": 0, "explanation": "T1W images give the best anatomic detail of erosions and the bright fat deposition seen after inflammation."}, {"q": "On these semi-coronal T1 images through the SI joints, on which side of the joint do erosions of sacroiliitis usually appear first?", "options": ["Sacral side", "Both sides equally from the start", "Only at the upper ligamentous part", "Iliac side"], "answer_index": 3, "explanation": "The cartilage on the iliac side is thinner, so erosions and sclerosis typically begin there in the lower synovial part of the joint."}]}, {"modality": "MRI", "region": "spine", "region_label": "Spine", "exam": "Lumbar plexus", "image": {"file": "mri__spine__lumbar-plexus.jpg", "caption": "MR neurography of the posterior pelvis showing the lumbosacral plexus and sciatic nerves.", "credit": "Aaron Filler", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Bilateral_Sciatic_Neurography.jpg"}, "questions": [{"q": "This MR neurography image shows the lumbosacral plexus and sciatic nerves as bright structures. What kind of sequence produces this?", "options": ["T1-weighted without fat suppression", "Heavily T2-weighted fat-suppressed imaging (e.g., 3D STIR)", "Time-of-flight angiography", "Opposed-phase GRE"], "answer_index": 1, "explanation": "Neurography uses strong T2 weighting with uniform fat suppression so nerves stand out against dark fat and muscle."}, {"q": "The lumbar plexus is formed by the ventral rami of which nerve roots?", "options": ["C5–T1", "S2–S4", "L1–L4, often with a T12 contribution", "T1–T6"], "answer_index": 2, "explanation": "The lumbar plexus arises from L1–L4 (plus T12) and gives rise to the femoral and obturator nerves."}, {"q": "Within which muscle does the lumbar plexus form, making it a key landmark on axial images?", "options": ["Psoas major", "Quadratus femoris", "Gluteus maximus", "Rectus abdominis"], "answer_index": 0, "explanation": "The plexus forms within the substance of the psoas major, so axial images through the psoas are used to trace its branches."}]}, {"modality": "MRI", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Shoulder", "image": {"file": "mri__upper_extremity__shoulder.jpg", "caption": "Coronal oblique fat-suppressed shoulder MRI showing subacromial impingement with a partial supraspinatus tear.", "credit": "RSatUSZ", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Subacromial_Impingement_with_Supraspinatus_Rupture.jpg"}, "questions": [{"q": "How should the arm be positioned for a routine shoulder MRI?", "options": ["At the side in neutral or slight external rotation", "In full internal rotation across the chest", "Abducted overhead", "Flexed 90° at the shoulder"], "answer_index": 0, "explanation": "Internal rotation makes the supraspinatus and infraspinatus tendons overlap; neutral to slight external rotation lays them out clearly."}, {"q": "This coronal oblique fat-suppressed image shows the tendon passing beneath the acromion. Which rotator cuff tendon is most often involved in subacromial impingement?", "options": ["Subscapularis", "Teres minor", "Supraspinatus", "Long head of triceps"], "answer_index": 2, "explanation": "The supraspinatus runs through the narrow space under the acromion and coracoacromial arch, where it is compressed in impingement."}, {"q": "Magic angle artifact can make a normal supraspinatus tendon look bright. On which sequences and at what angle does it occur?", "options": ["Long-TE T2 sequences, tendon parallel to B0", "Short-TE sequences (T1, PD, GRE), tendon about 55° to B0", "STIR only, tendon perpendicular to B0", "Any sequence, any angle"], "answer_index": 1, "explanation": "At about 55° to the main field, dipolar effects in collagen lengthen T2, adding signal on short-TE images; it disappears on long-TE T2."}]}, {"modality": "MRI", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Shoulder arthrogram", "image": {"file": "mri__upper_extremity__shoulder-arthrogram.jpg", "caption": "Axial fat-suppressed PD image from a direct shoulder MR arthrogram, with contrast distending the joint.", "credit": "RSatUSZ", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:MRI._Edema_of_the_infraspinatus_tendon..jpg"}, "questions": [{"q": "Before MR imaging for a shoulder arthrogram, the intra-articular injection is most commonly guided by:", "options": ["Palpation only, without imaging", "Nuclear medicine imaging", "MR fluoroscopy in the scanner", "Fluoroscopy (or ultrasound)"], "answer_index": 3, "explanation": "Fluoroscopic or ultrasound guidance confirms needle placement within the glenohumeral joint before the patient moves to MRI."}, {"q": "Which sequences form the core of a direct shoulder MR arthrogram after intra-articular gadolinium?", "options": ["Fat-suppressed T1-weighted images in three planes, plus at least one fat-suppressed T2 sequence", "Non-contrast GRE only", "Diffusion-weighted imaging only", "Time-of-flight MRA"], "answer_index": 0, "explanation": "Fat-suppressed T1 shows the bright distended joint contrast; a fluid-sensitive sequence detects edema and cysts that do not fill with contrast."}, {"q": "On this axial fat-suppressed arthrogram image, the capsule is distended by bright contrast. Why is imaging started soon after injection (ideally within about 30–60 minutes)?", "options": ["Gadolinium becomes ferromagnetic with time", "The patient must stay NPO", "Contrast is resorbed and diluted over time, reducing joint distension", "SAR rises after an hour"], "answer_index": 2, "explanation": "Delays let fluid diffuse out of and into the joint, so distension and contrast concentration fall and labral detail is lost."}]}, {"modality": "MRI", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Elbow", "image": {"file": "mri__upper_extremity__elbow.jpg", "caption": "Coronal fat-suppressed PD elbow MRI showing lateral epicondylitis at the common extensor origin.", "credit": "Hellerhoff", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Epicondylitis_lateralis_des_Ellenbogens_49W_-_MR_PDW_FS_-_001.jpg"}, "questions": [{"q": "Fat suppression fails on an elbow scanned at the patient's side, far from isocenter. What is the best fix?", "options": ["Increase the slice gap", "Use a body coil instead of a dedicated coil", "Shorten the TR", "Reposition so the elbow is as close to isocenter as possible (e.g., prone with arm overhead)"], "answer_index": 3, "explanation": "Field homogeneity is best at isocenter; off-center anatomy suffers from poor spectral fat saturation and lower SNR."}, {"q": "On a routine elbow exam such as this coronal study, the axial slices should cover from the distal humerus down to at least the:", "options": ["Radial tuberosity, to include the distal biceps insertion", "Olecranon tip only", "Mid-humerus", "Distal radioulnar joint"], "answer_index": 0, "explanation": "The distal biceps tendon inserts on the radial tuberosity, so axial coverage must extend past it."}, {"q": "Which special position is used to show the distal biceps tendon along its length in one plane?", "options": ["ABER (abduction, external rotation)", "Prone with the wrist pronated", "FABS (flexed elbow, abducted shoulder, supinated forearm)", "Arm at the side in full pronation"], "answer_index": 2, "explanation": "In the FABS position the tendon lies in a single plane from musculotendinous junction to the radial tuberosity."}]}, {"modality": "MRI", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Wrist", "image": {"file": "mri__upper_extremity__wrist.jpg", "caption": "Coronal T1-weighted wrist MRI showing lunate collapse and low signal in Kienböck disease (cropped from a combined figure).", "credit": "Xie et al.", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:RM-malattia_di_Kienbock.png"}, "questions": [{"q": "Which plane best shows the triangular fibrocartilage complex (TFCC) of the wrist?", "options": ["Sagittal", "Axial", "Coronal", "Oblique sagittal through the thumb"], "answer_index": 2, "explanation": "The TFCC spans from the radius to the ulnar styloid, so thin coronal slices show it along its length."}, {"q": "This coronal T1 image of the wrist shows a collapsed lunate with diffusely low signal. What is the most likely diagnosis?", "options": ["Scapholunate ligament tear", "Kienböck disease (avascular necrosis of the lunate)", "Ganglion cyst", "Carpal tunnel syndrome"], "answer_index": 1, "explanation": "Loss of normal fatty marrow signal on T1 with lunate collapse is the hallmark of Kienböck disease."}, {"q": "Kienböck disease is associated with which anatomic variant seen on wrist imaging?", "options": ["Negative ulnar variance (short ulna)", "Positive ulnar variance (long ulna)", "Bipartite scaphoid", "Os styloideum"], "answer_index": 0, "explanation": "A short ulna concentrates load on the lunate; positive variance is instead linked to ulnar impaction."}]}, {"modality": "MRI", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Hand", "image": {"file": "mri__upper_extremity__hand.jpg", "caption": "Coronal T1-weighted hand MRI before (a) and after (b) contrast in psoriatic arthritis.", "credit": "McQueen F, Lassere M, Østergaard M", "license": "CC BY 2.0", "page_url": "https://commons.wikimedia.org/wiki/File:Psoriatic_arthritis_fingers_ar1934-1.gif"}, "questions": [{"q": "These pre- and post-contrast coronal T1 hand images show bright areas around the finger joints after contrast (arrows). What does this enhancement indicate in inflammatory arthritis?", "options": ["Calcified cartilage", "Normal tendon", "Old healed fractures", "Active synovitis or enthesitis"], "answer_index": 3, "explanation": "Thickened, inflamed synovium and entheses take up gadolinium, so enhancement marks active disease."}, {"q": "How can enhancement be made easier to see on a hand MRI?", "options": ["Subtract the pre-contrast images from identical post-contrast images", "Increase the slice gap", "Use a long TE on the post-contrast series", "Image in a different plane after contrast"], "answer_index": 0, "explanation": "Subtraction removes background signal so only the change caused by gadolinium remains; the two series must use the same parameters."}, {"q": "Why is fat suppression added to post-contrast T1 images of the hand?", "options": ["To reduce SAR", "To shorten the scan", "So enhancing tissue stands out from bright fat and marrow", "To remove flow artifact from tendons"], "answer_index": 2, "explanation": "On plain T1, fat and gadolinium are both bright; suppressing fat makes the enhancement conspicuous."}]}, {"modality": "MRI", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Fingers", "image": {"file": "mri__upper_extremity__fingers.jpg", "caption": "Sagittal fat-suppressed T2-weighted MRI of an index finger in psoriatic arthritis.", "credit": "McQueen F, Lassere M, Østergaard M", "license": "CC BY 2.0", "page_url": "https://commons.wikimedia.org/wiki/File:Psoriatic_arthritis_digit_ar1934-2.gif"}, "questions": [{"q": "On a sagittal fat-suppressed T2 image of a finger, such as this one, what does bright fluid surrounding the flexor tendon indicate?", "options": ["Normal tendon", "Fluid and inflammation in the tendon sheath (tenosynovitis)", "Lipoma", "Magic angle artifact"], "answer_index": 1, "explanation": "Bright fluid surrounding the tendon on fluid-sensitive images indicates tenosynovitis, as seen in dactylitis."}, {"q": "For a high-resolution MRI of a single finger, which coil gives the best SNR?", "options": ["The body coil", "A large flexible torso array", "A head coil", "A small dedicated surface (microscopy) coil placed over the finger"], "answer_index": 3, "explanation": "Small surface coils sit close to the anatomy and allow the very small FOV and voxel sizes that finger imaging needs."}, {"q": "In rock climbers, rupture of which flexor pulley most often lets the flexor tendons bowstring away from the phalanx?", "options": ["A2 pulley", "A5 pulley", "C1 pulley", "Extensor hood"], "answer_index": 0, "explanation": "The A2 pulley at the proximal phalanx is the strongest and most often injured; its rupture increases the tendon-to-bone distance."}]}, {"modality": "MRI", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Thumb", "image": null, "questions": [{"q": "Skier's (gamekeeper's) thumb is an injury to which structure?", "options": ["Radial collateral ligament of the thumb IP joint", "Ulnar collateral ligament of the thumb MCP joint", "Scapholunate ligament", "Flexor pollicis longus pulley"], "answer_index": 1, "explanation": "A forced radial stress on the thumb tears the ulnar collateral ligament of the first metacarpophalangeal joint."}, {"q": "A Bennett fracture, which may be assessed on thumb imaging, involves which location?", "options": ["Distal phalanx tuft of the thumb", "Scaphoid waist", "Intra-articular base of the first metacarpal at the CMC joint", "Neck of the fifth metacarpal"], "answer_index": 2, "explanation": "A Bennett fracture is an intra-articular fracture-dislocation at the base of the first metacarpal; a boxer's fracture is the fifth metacarpal neck."}, {"q": "How are the imaging planes prescribed for a dedicated thumb MRI?", "options": ["Exactly the same as for the hand", "Axial to the table only", "Using the wrist's coronal plane", "Obliquely, aligned to the thumb's own long and short axes"], "answer_index": 3, "explanation": "The thumb is rotated relative to the fingers, so planes are angled to the first ray to show the collateral ligaments in true profile."}]}, {"modality": "MRI", "region": "upper_extremity", "region_label": "Upper Extremity", "exam": "Humerus/forearm (long bones)", "image": {"file": "mri__upper_extremity__humerus-forearm-long-bones.jpg", "caption": "Axial forearm MRI (post-contrast T1 FS left, T2 right) showing multifocal pyomyositis.", "credit": "Hellerhoff", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Pyomyositis_multifokal_-_MRT_Unterarm_T1FSKM_und_T2.jpg"}, "questions": [{"q": "When imaging a suspected primary bone tumor of the humerus, what should the long-axis T1 series include?", "options": ["Only the lesion with a small FOV", "The lesion and the nearest joint only", "The entire bone, including both adjacent joints", "Both humeri for comparison only"], "answer_index": 2, "explanation": "Covering the whole bone allows full tumor extent to be measured and detects skip lesions elsewhere in the same bone."}, {"q": "These axial forearm images (left: post-contrast T1 FS; right: T2) show several rim-enhancing fluid collections within the muscles. What is the most likely diagnosis?", "options": ["Pyomyositis with intramuscular abscesses", "Normal muscle", "Lipoma", "Myositis ossificans"], "answer_index": 0, "explanation": "Fluid collections with an enhancing rim inside muscle, with surrounding diffuse enhancement, are typical of infectious myositis with abscesses."}, {"q": "For a coronal long-axis image of the entire humerus with a rectangular FOV, how should the frequency-encoding direction be set?", "options": ["Left to right, across the arm", "Superior to inferior, along the long axis of the bone", "Anterior to posterior", "It does not matter"], "answer_index": 1, "explanation": "Placing frequency along the long dimension prevents wrap there without extra time, while the narrow phase direction allows a rectangular FOV."}]}, {"modality": "MRI", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Hip", "image": {"file": "mri__lower_extremity__hip.jpg", "caption": "Coronal T1-weighted hip MRI showing an occult subcapital femoral neck fracture.", "credit": "Mikael Häggström, M.D.", "license": "CC0", "page_url": "https://commons.wikimedia.org/wiki/File:T1_TSE_MRI_of_hip_fracture.jpg"}, "questions": [{"q": "For a hip MRI, how are the legs usually positioned to show the femoral necks best?", "options": ["Externally rotated (toes pointing out)", "Flexed at 90°", "Abducted in a frog-leg position", "Mildly internally rotated with the toes together (often taped)"], "answer_index": 3, "explanation": "Internal rotation offsets normal femoral anteversion so the femoral neck lies flat in the coronal plane."}, {"q": "This coronal T1 image of an elderly woman after a fall shows a dark line through the subcapital femoral neck with low-signal surrounding marrow. What does it show?", "options": ["Normal growth plate scar", "Avascular necrosis", "Nondisplaced (occult) femoral neck fracture", "Transient osteoporosis"], "answer_index": 2, "explanation": "A linear low-signal band on T1 crossing the neck represents the fracture line, often invisible on radiographs."}, {"q": "Acetabular labral tears are most commonly found in which part of the labrum?", "options": ["Anterosuperior", "Posteroinferior", "Inferior (at the transverse ligament)", "Medial"], "answer_index": 0, "explanation": "Most labral tears, including those from femoroacetabular impingement, are in the anterosuperior labrum."}]}, {"modality": "MRI", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Knee", "image": {"file": "mri__lower_extremity__knee.jpg", "caption": "Sagittal T1-weighted knee MRI showing normal anterior and posterior cruciate ligaments (arrows).", "credit": "Lykissas MG, et al.", "license": "CC BY-SA 2.0", "page_url": "https://commons.wikimedia.org/wiki/File:MRT_ACL_PCL_01.jpg"}, "questions": [{"q": "Which sequence type is preferred for detecting meniscal tears?", "options": ["Long-TE T2-weighted spin echo only", "Short-TE proton-density weighted FSE", "Time-of-flight GRE", "Diffusion-weighted EPI"], "answer_index": 1, "explanation": "Short-TE PD images are most sensitive to abnormal signal reaching the meniscal surface; long-TE images miss many tears."}, {"q": "How are sagittal knee slices angled to show the full length of the ACL?", "options": ["Perpendicular to the patellar tendon", "Exactly parallel to the table edge with no angle", "Parallel to the medial border of the lateral femoral condyle on an axial image", "Parallel to the tibial plateau on a coronal image"], "answer_index": 2, "explanation": "The ACL runs obliquely from the lateral femoral condyle, so angling sagittals along that condyle shows the ligament in one or two slices."}, {"q": "On this sagittal T1 knee image, arrows mark the cruciate ligaments. How does a normal PCL appear?", "options": ["Thin and striated with intermediate signal", "Bright on all sequences", "Absent on sagittal images", "A thick, uniformly dark, gently curved band"], "answer_index": 3, "explanation": "The normal PCL is a thick, homogeneously low-signal arc; the ACL is thinner and often slightly striated."}]}, {"modality": "MRI", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Ankle", "image": {"file": "mri__lower_extremity__ankle.jpg", "caption": "Sagittal STIR of the hindfoot showing an occult calcaneal fracture (arrowheads).", "credit": "Jarraya M, et al.", "license": "CC BY 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:STIR_MRI_of_of_calcaneal_fracture.jpg"}, "questions": [{"q": "This sagittal STIR image of the hindfoot shows a linear abnormality in the calcaneus (arrowheads) surrounded by bright marrow signal, with normal radiographs. What is the most likely finding?", "options": ["Normal marrow", "Occult (stress or trauma) fracture with marrow edema", "Calcaneal lipoma", "Haglund deformity"], "answer_index": 1, "explanation": "A fracture line with surrounding marrow edema on STIR shows a fracture that radiographs can miss."}, {"q": "How is the foot usually positioned for ankle MRI to reduce magic angle effect in the peroneal tendons?", "options": ["About 20° of plantar flexion", "Maximal dorsiflexion", "Full eversion", "Foot hanging off the table"], "answer_index": 0, "explanation": "Slight plantar flexion changes the angle of the tendons curving around the malleolus away from 55° to the main field."}, {"q": "On axial images, what is the shape of a normal Achilles tendon?", "options": ["Round with central high signal", "Bright and striated", "Flat to concave anteriorly (crescent-shaped), uniformly dark", "Bilobed with a central cleft"], "answer_index": 2, "explanation": "A convex anterior margin or a thickened, rounded tendon suggests tendinosis; the normal tendon is a flat, dark crescent."}]}, {"modality": "MRI", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Foot", "image": {"file": "mri__lower_extremity__foot.jpg", "caption": "Sagittal fat-suppressed T2-weighted foot MRI showing marrow edema in the talus, navicular, and cuneiform.", "credit": "Radschläger13", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Knochenmark%C3%B6dem.MRT-T2-Wichtung.jpg"}, "questions": [{"q": "This sagittal fat-suppressed T2 image of the midfoot shows bright signal in the talus, navicular, and cuneiform. What does this signal represent?", "options": ["Bone marrow edema", "Fatty marrow", "Normal cartilage", "Gadolinium enhancement"], "answer_index": 0, "explanation": "On fluid-sensitive fat-suppressed images, marrow edema from stress, trauma, or arthritis appears bright against dark fatty marrow."}, {"q": "Which tendon inserts mainly on the navicular tuberosity and is commonly evaluated for dysfunction in adult acquired flatfoot?", "options": ["Peroneus brevis", "Achilles", "Extensor hallucis longus", "Posterior tibial tendon"], "answer_index": 3, "explanation": "Posterior tibial tendon degeneration and tear lead to loss of the medial arch; the tendon is followed around the medial malleolus to the navicular."}, {"q": "The Lisfranc ligament, assessed on foot MRI after midfoot injury, connects which bones?", "options": ["Calcaneus to cuboid", "Talus to navicular", "First to second metatarsal heads", "Medial cuneiform to the base of the second metatarsal"], "answer_index": 3, "explanation": "This strong ligament stabilizes the tarsometatarsal joint; its disruption leads to Lisfranc instability."}]}, {"modality": "MRI", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Femur/tibia (long bones)", "image": {"file": "mri__lower_extremity__femur-tibia-long-bones.jpg", "caption": "Coronal STIR of the lower leg showing periosteal edema along the tibia (shin splints).", "credit": "MBq", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Shinsplint-mri.jpg"}, "questions": [{"q": "This coronal STIR image of a runner's lower leg shows bright signal along the surface of the tibia but no fracture line. What is the earliest MRI sign of tibial stress injury?", "options": ["Cortical fracture line on T1", "Periosteal edema on fat-suppressed T2/STIR", "Fatty marrow conversion", "Muscle atrophy"], "answer_index": 1, "explanation": "Stress injury progresses from periosteal edema to marrow edema and finally to a visible fracture line."}, {"q": "Why are both legs often included in a coronal STIR of the thighs or lower legs?", "options": ["To compare with the asymptomatic side", "It is required by MR safety rules", "To reduce SAR", "To avoid aliasing in the slice direction"], "answer_index": 0, "explanation": "Side-by-side imaging helps show subtle asymmetric edema or masses against normal anatomy."}, {"q": "How does a stress fracture line typically appear on T1-weighted images?", "options": ["A bright line parallel to the cortex", "No visible change", "A dark line running roughly perpendicular to the cortex into the medullary cavity", "A round bright nodule"], "answer_index": 2, "explanation": "The fracture line is low signal on T1 and usually runs across the cortex, surrounded by marrow edema on STIR."}]}, {"modality": "MRI", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Arthrogram", "image": null, "questions": [{"q": "How does indirect MR arthrography differ from direct MR arthrography?", "options": ["Gadolinium is given intravenously and reaches the joint by diffusion, helped by exercising the joint", "Saline is injected into the joint", "No contrast is used", "Iodinated contrast is injected into the joint"], "answer_index": 0, "explanation": "In indirect arthrography the joint fluid enhances after IV gadolinium and joint movement; there is no joint puncture."}, {"q": "For a hip MR arthrogram, where is the needle usually directed under imaging guidance?", "options": ["The lesser trochanter", "The anterior femoral head–neck junction", "The ischial tuberosity", "The acetabular roof through the iliac bone"], "answer_index": 1, "explanation": "The anterior head–neck junction is inside the capsule and away from the femoral neurovascular bundle when the approach is correct."}, {"q": "Why is a small amount of iodinated contrast often injected first during a fluoroscopically guided MR arthrogram?", "options": ["To increase T1 signal on MRI", "To prevent allergic reactions to gadolinium", "To replace the gadolinium", "To confirm intra-articular needle position before the gadolinium mixture is given"], "answer_index": 3, "explanation": "Seeing contrast flow away from the needle tip into the joint confirms placement and avoids extra-articular injection."}]}, {"modality": "MRI", "region": "lower_extremity", "region_label": "Lower Extremity", "exam": "Runoff MRA (vascular extremities)", "image": null, "questions": [{"q": "In moving-table (bolus-chase) runoff MRA, which station is typically acquired first?", "options": ["The aortoiliac (abdomen/pelvis) station", "The calf/foot station", "The thigh station", "All stations at once"], "answer_index": 0, "explanation": "The bolus reaches the aorta first, so imaging moves from the aortoiliac station down the legs ahead of venous enhancement."}, {"q": "Venous contamination often obscures the calf arteries on runoff MRA. Which approach most directly addresses this?", "options": ["Increasing the slice thickness", "A separate time-resolved (or hybrid) acquisition of the calf station", "Using the body coil only", "Imaging the calves last with a longer delay"], "answer_index": 1, "explanation": "Imaging the calves with a time-resolved or early dedicated injection captures the arterial phase before the leg veins fill."}, {"q": "A patient with severe renal impairment needs evaluation of leg arteries. Which MRA technique avoids gadolinium?", "options": ["Phase-contrast imaging of the brain", "Diffusion-weighted imaging", "An ECG-gated non-contrast method such as QISS or fresh-blood imaging", "Contrast-enhanced 3D GRE with half-dose gadolinium"], "answer_index": 2, "explanation": "Non-contrast runoff methods use cardiac gating and flow-dependent signal to show arteries without any contrast agent."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Craniocaudal (CC) view", "exam": "Screening mammography (CC)", "image": {"file": "mammography__breast__screening-mammography-cc.jpg", "caption": "Bilateral digital screening mammogram, craniocaudal (CC) views.", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:40F_CC_DMMG.png"}, "questions": [{"q": "Which breast tissue must be included on the CC view because it may not be fully seen on the MLO?", "options": ["Axillary tail", "Inferior tissue at the IMF", "Lateral tissue near the latissimus", "Medial tissue"], "answer_index": 3, "explanation": "Medial posterior tissue is easily missed on the MLO, so the CC must include all medial tissue without rotation."}, {"q": "On this bilateral screening CC image, the posterior breast edge is shown. In roughly what share of well-positioned CC views is the pectoralis muscle actually visible?", "options": ["Nearly 100%", "About 75%", "About 30–40%", "Under 5%"], "answer_index": 2, "explanation": "The pectoral muscle appears on only about a third of good CC views; when it is absent, the PNL comparison with the MLO is used to judge posterior coverage."}, {"q": "To include as much tissue as possible on the CC, the technologist first lifts the breast and then:", "options": ["Pulls the breast tissue forward onto the receptor, away from the chest wall, before compressing", "Pushes the breast back toward the chest wall", "Rotates the patient 45° toward the receptor", "Places the arm on the opposite side behind the head"], "answer_index": 0, "explanation": "Lifting the mobile inferior border and pulling tissue forward brings posterior tissue onto the receptor before the paddle locks it in place."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Craniocaudal (CC) view", "exam": "Diagnostic mammography", "image": {"file": "mammography__breast__diagnostic-mammography.jpg", "caption": "Bilateral CC mammogram showing a dense, irregular mass in the right breast (diagnostic work-up).", "credit": "SCiardullo", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:N%C3%B3dulo_BR_5_proyecci%C3%B3n_CC.JPG"}, "questions": [{"q": "Which patient should be scheduled for a diagnostic rather than a screening mammogram?", "options": ["A 45-year-old with no symptoms due for her annual exam", "A 52-year-old with a new palpable lump in the right breast", "A 40-year-old starting baseline screening", "A 60-year-old with a normal exam last year and no complaints"], "answer_index": 1, "explanation": "A new symptom such as a palpable lump calls for a diagnostic exam tailored to the problem rather than routine screening."}, {"q": "On this bilateral CC image, a dense, irregular mass is present in one breast. If the radiologist considers a finding highly suggestive of malignancy (≥95%), which BI-RADS category applies?", "options": ["Category 2", "Category 3", "Category 4A", "Category 5"], "answer_index": 3, "explanation": "BI-RADS 5 means highly suggestive of malignancy, with a likelihood of 95% or more; tissue diagnosis is recommended."}, {"q": "How does the workflow of a diagnostic mammogram typically differ from screening?", "options": ["Only the MLO views are taken", "The patient leaves before any images are reviewed", "A radiologist reviews images during the visit and directs additional views as needed", "No compression is used"], "answer_index": 2, "explanation": "Diagnostic exams are monitored by a radiologist who can request spot, magnification or other views and ultrasound before the patient leaves."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Craniocaudal (CC) view", "exam": "Exaggerated CC lateral/medial (XCCL, XCCM)", "image": {"file": "mammography__breast__exaggerated-cc-lateral-medial-xccl-xccm.jpg", "caption": "Bilateral CC projection extended toward the axilla, showing lateral tissue as on an exaggerated CC lateral (XCCL).", "credit": "SCiardullo", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Patron_predominio_fibroadiposo_CC.JPG"}, "questions": [{"q": "This CC image extends far toward the axilla, giving a tear-drop outline. Which supplemental projection does it most resemble?", "options": ["Exaggerated CC lateral (XCCL)", "Cleavage (valley) view", "Lateromedial (LM)", "Caudocranial (FB)"], "answer_index": 0, "explanation": "Rotating the patient so the lateral breast and tail are brought onto the receptor in a CC orientation produces the XCCL."}, {"q": "How is the patient positioned for an XCCL compared with a standard CC?", "options": ["The patient is rotated so the medial breast is centered over the receptor", "The patient is rotated so the lateral breast and axillary tail are brought onto the receptor", "The tube is angled 45° as for the MLO", "The receptor is lowered below the inframammary fold"], "answer_index": 1, "explanation": "For XCCL the patient turns so lateral tissue lies on the receptor; the tube stays vertical or is angled only about 5° laterally."}, {"q": "A finding lies far posteriorly in the medial breast and is only partly seen on the routine CC. Which view is the best next step?", "options": ["XCCL", "Axillary tail view", "Exaggerated CC medial (XCCM)", "90° LM with implant included"], "answer_index": 2, "explanation": "The XCCM rotates the patient to bring deep medial tissue onto the receptor while keeping the CC orientation."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Craniocaudal (CC) view", "exam": "DBT CC acquisition", "image": null, "questions": [{"q": "How are the individual low-dose projections of a DBT acquisition turned into the slices the radiologist reads?", "options": ["They are added together into one 2D image without processing", "Each projection is read separately as a stereo pair", "Ultrasound software converts them into 3D", "Reconstruction algorithms such as filtered back-projection or iterative methods"], "answer_index": 3, "explanation": "The projection set is mathematically reconstructed (filtered back-projection or iterative reconstruction) into a stack of thin slices parallel to the detector."}, {"q": "Compared with 2D mammography alone, DBT screening mainly reduces recalls caused by:", "options": ["Skin folds", "Overlapping normal tissue that mimics a lesion (summation)", "Patient motion", "Calcifications in vessels"], "answer_index": 1, "explanation": "By separating tissue layers, DBT resolves many pseudo-lesions from superimposed normal tissue, lowering recall rates."}, {"q": "On a DBT CC data set, the slice in which a lesion is sharpest helps to indicate:", "options": ["Its approximate depth (height) within the compressed breast", "Its BI-RADS category", "The kVp used", "Whether the lesion enhances with contrast"], "answer_index": 0, "explanation": "Each slice corresponds to a height above the detector, so the in-focus slice gives the lesion's approximate superior–inferior position on a CC."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Mediolateral oblique (MLO) view", "exam": "Screening mammography (MLO)", "image": {"file": "mammography__breast__screening-mammography-mlo.jpg", "caption": "Bilateral digital screening mammogram, mediolateral oblique (MLO) views.", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:40F_MLO_DMMG.png"}, "questions": [{"q": "Which describes optimal pectoral muscle on an MLO?", "options": ["A thin straight strip ending at the top of the image", "Absent, so the breast is not obscured", "Wide at the axilla, convex anteriorly, reaching to or below the PNL", "Concave and ending well above the nipple level"], "answer_index": 2, "explanation": "A relaxed, convex pectoralis that extends to the PNL shows that posterior tissue was pulled into the field."}, {"q": "On this bilateral screening MLO image the right and left views are displayed back to back as mirror images. The main reason for this hanging convention is to:", "options": ["Reduce dose", "Help the radiologist compare the breasts for symmetry", "Meet the laterality marker rule", "Hide the pectoral muscle"], "answer_index": 1, "explanation": "Mirror-image display makes asymmetries, new densities and distortion easier to spot between the two breasts."}, {"q": "When compression is applied on the MLO, the upper corner of the paddle should come to rest:", "options": ["Just below the clavicle", "At the level of the nipple", "Over the humeral head", "Under the inframammary fold"], "answer_index": 0, "explanation": "The paddle edge should sit just inferior to the clavicle so it holds the upper and axillary tissue without riding on bone."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Mediolateral oblique (MLO) view", "exam": "DBT MLO acquisition", "image": {"file": "mammography__breast__dbt-mlo-acquisition.jpg", "caption": "Galactography: (a) full-field digital image and (b) digital breast tomosynthesis slice showing an intraductal filling defect (arrow).", "credit": "Marco Moschetta et al. (Eur Radiol Exp 2020)", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Full-field_digital_(FFD)-galactography_and_Digital_breast_tomosynthesis_(DBT)-galactography.png"}, "questions": [{"q": "Panels (a) 2D and (b) DBT on this galactogram show the same breast. What does the DBT slice reveal that the 2D image does not?", "options": ["A skin fold", "Motion blur", "A small intraductal filling defect hidden by overlapping contrast-filled ducts", "A fat-fluid level"], "answer_index": 2, "explanation": "Thin DBT slices remove overlapping ducts and tissue, so a small papilloma appears as a filling defect (arrow) not visible on 2D."}, {"q": "Calcification clusters can be spread across several thin DBT slices. Which display option helps show the whole cluster at once?", "options": ["Viewing only the first slice", "Reducing the window width to zero", "Inverting the grayscale", "Thicker slabs or a synthesized 2D image"], "answer_index": 3, "explanation": "Slab images combine several thin slices and a synthesized 2D image summarizes the stack, making the cluster's shape and extent easier to judge."}, {"q": "Galactography (ductography), as shown in this image, is typically indicated for:", "options": ["Spontaneous discharge from a single duct", "Bilateral milky discharge from many ducts", "Routine screening of dense breasts", "Breast implant evaluation"], "answer_index": 0, "explanation": "Single-duct spontaneous (often bloody or clear) discharge is the classic indication; a cannulated duct is filled with contrast to show intraductal lesions."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Axillary tail and upper outer quadrant", "exam": "Axillary tail (AT) view", "image": null, "questions": [{"q": "Which statement best describes the axillary tail (AT) view?", "options": ["A CC view of the whole breast with the tube angled 15° medially", "An oblique view focused on the axillary tail, with the receptor angled to parallel the tail and a smaller compression area", "A true lateral of the axilla with the arm raised overhead", "A magnification view of the nipple"], "answer_index": 1, "explanation": "The AT view images only the tail of Spence, angling the C-arm so the receptor parallels the tail and compressing that region."}, {"q": "Why is complete coverage of the upper outer breast and tail emphasized?", "options": ["It contains no lymph nodes", "It is the only area that can be compressed", "It holds the most glandular tissue and is where cancers most often arise", "It is always fatty and easy to read"], "answer_index": 2, "explanation": "The upper outer quadrant contains the greatest volume of glandular tissue, so roughly half of breast cancers occur there."}, {"q": "Which appearance of an axillary lymph node on mammography is most suspicious?", "options": ["Small oval node with a fatty center", "Node seen on prior exams without change", "Kidney-shaped node under 1 cm", "Enlarged, round, dense node with loss of its fatty hilum"], "answer_index": 3, "explanation": "Loss of the fatty hilum, rounding, increased density and enlargement suggest metastatic or lymphomatous involvement."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Axillary tail and upper outer quadrant", "exam": "MLO with axilla included", "image": {"file": "mammography__breast__mlo-with-axilla-included.jpg", "caption": "Bilateral MLO mammogram including the axillary region and pectoral muscle; predominantly fatty breasts.", "credit": "SCiardullo", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Patron_predominio_fibroadiposo_OML.JPG"}, "questions": [{"q": "For an MLO that includes the axilla, the patient's arm on the side being imaged should be:", "options": ["Raised straight overhead", "Relaxed over the top of the receptor with the elbow bent", "Held tightly against the side", "Placed behind the back"], "answer_index": 1, "explanation": "A relaxed arm draped over the receptor with the elbow flexed relaxes the pectoral muscle, letting the axillary tissue be pulled into the field."}, {"q": "If the receptor corner is placed too far back in the axilla, which muscle is caught and limits compression?", "options": ["Latissimus dorsi", "Serratus anterior", "Pectoralis minor", "Rectus abdominis"], "answer_index": 0, "explanation": "The receptor edge belongs just behind the pectoral muscle; going too far posterior traps the latissimus dorsi and prevents firm compression."}, {"q": "This MLO shows breasts made up almost entirely of fat. Which BI-RADS breast composition category is that?", "options": ["Category d", "Category c", "Category b", "Category a"], "answer_index": 3, "explanation": "Category a is almost entirely fatty; b scattered fibroglandular, c heterogeneously dense, d extremely dense."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Axillary tail and upper outer quadrant", "exam": "Lateral (ML) view", "image": null, "questions": [{"q": "Compared with the MLO, how does the pectoral muscle usually appear on a true 90° ML view?", "options": ["Narrower, because the receptor is not angled parallel to the muscle", "Wider and extending below the nipple", "Exactly the same", "It is never seen"], "answer_index": 0, "explanation": "The MLO angle matches the pectoral slope; a straight 90° lateral shows less muscle, often only a thin strip."}, {"q": "The CC and 90° lateral are described as orthogonal views. This means they:", "options": ["Use the same tube angle", "Are taken 90° apart, allowing true localization of a finding in three dimensions", "Are both oblique", "Are taken at different kVp settings"], "answer_index": 1, "explanation": "Two projections at right angles let the finding's position be triangulated, which is why CC plus 90° lateral are used for localization and clip documentation."}, {"q": "Which part of the breast is less completely shown on a 90° ML than on the MLO?", "options": ["The nipple", "Medial tissue", "The posterior upper outer tissue and axillary tail", "The skin line"], "answer_index": 2, "explanation": "The oblique MLO follows the pectoral muscle into the axilla; the straight lateral includes less of the upper outer posterior tissue and tail."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Implant-displaced (ID) views", "exam": "Standard CC and MLO with implant included", "image": {"file": "mammography__breast__standard-cc-and-mlo-with-implant-included.jpg", "caption": "Bilateral CC views with retroglandular implants included in the field (standard implant views).", "credit": "SCiardullo", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:BR2_-_Implantes_mamarios_II.JPG"}, "questions": [{"q": "How are the standard CC and MLO views taken with the implant in the field?", "options": ["Full compression with AEC", "Manual exposure with only enough compression to reduce motion", "AEC with the grid removed", "Magnification technique"], "answer_index": 1, "explanation": "An implant blocks AEC readings and could be damaged by firm compression, so manual technique and light compression are used."}, {"q": "On these CC views the implant lies directly behind the glandular tissue and in front of the pectoral muscle. This placement is called:", "options": ["Subpectoral", "Retroglandular (subglandular)", "Intramuscular", "Prepectoral fat graft"], "answer_index": 1, "explanation": "A retroglandular implant sits between the gland and the muscle; it is usually harder to displace than a subpectoral implant."}, {"q": "On follow-up mammography, a saline implant appears much smaller and folded. This most likely indicates:", "options": ["Capsular calcification", "Normal settling", "Rupture with deflation as the saline is absorbed", "Silicone gel bleed"], "answer_index": 2, "explanation": "Saline leaking from a ruptured shell is absorbed by the body, so the implant collapses (deflates), which is clinically and radiographically obvious."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Implant-displaced (ID) views", "exam": "Implant-displaced CC and MLO (Eklund)", "image": {"file": "mammography__breast__implant-displaced-cc-and-mlo-eklund.jpg", "caption": "Bilateral implant-displaced (Eklund) MLO views: implants pushed back, breast tissue pulled forward into compression.", "credit": "SCiardullo", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:BR2_-_Implantes_mamarios_IV.JPG"}, "questions": [{"q": "In the Eklund implant-displaced technique, the technologist:", "options": ["Pushes the breast tissue back toward the chest wall over the implant", "Images only the implant with magnification", "Pushes the implant back against the chest wall and pulls breast tissue forward into compression", "Angles the tube 15° to project the implant off the receptor"], "answer_index": 2, "explanation": "Displacing the implant posteriorly lets the anterior breast tissue be compressed and imaged without the implant overlapping it."}, {"q": "On these implant-displaced views the implant is mostly pushed out of the field. Which exposure approach is usually suitable?", "options": ["AEC, because the dense implant is largely outside the imaged area", "Manual low kVp with no compression", "Fluoroscopy", "AEC with the sensor under the implant"], "answer_index": 0, "explanation": "With the implant displaced, the compressed field is mainly breast tissue, so AEC can be used as on a normal view."}, {"q": "Compared with the standard implant views, the ID views apply:", "options": ["No compression at all", "Light compression across the implant", "Compression only to the axilla", "Full compression to the breast tissue anterior to the implant"], "answer_index": 3, "explanation": "Pulling the tissue forward over the displaced implant allows firm compression, improving tissue separation and detail."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Implant-displaced (ID) views", "exam": "90° lateral (ML) for encapsulated implants", "image": null, "questions": [{"q": "Capsular contracture around a breast implant is:", "options": ["Leakage of saline into the axilla", "Tightening of the fibrous scar capsule around the implant, making it firm and hard to move", "Migration of silicone into lymph nodes", "Calcification of the nipple"], "answer_index": 1, "explanation": "The body forms a fibrous capsule around every implant; when it contracts, the implant becomes firm, may distort, and is difficult to displace."}, {"q": "On the Baker scale, a breast that is hard, painful and visibly distorted from capsular contracture is grade:", "options": ["I", "II", "III", "IV"], "answer_index": 3, "explanation": "Baker IV describes a hard, painful, cold and abnormal-looking breast; grade I is soft and normal."}, {"q": "Before imaging a patient with implants, which information is most useful to record?", "options": ["Implant type (saline or silicone), placement, and any symptoms of rupture or recent surgery", "Her shoe size", "Her blood type", "The brand of her deodorant only"], "answer_index": 0, "explanation": "Implant type, location, history and symptoms guide view selection and help the radiologist interpret the images."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Implant-displaced (ID) views", "exam": "Breast MRI for implant integrity", "image": {"file": "mammography__breast__breast-mri-for-implant-integrity.jpg", "caption": "Axial breast MRI (color-mapped) of a patient with bilateral silicone implants.", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Breast_MRI_Implant_T1FSE_T2FSE_InPhase_STIR_Silicon_15.jpg"}, "questions": [{"q": "On this axial breast MRI of a patient with silicone implants, which sign indicates intracapsular rupture?", "options": ["Target sign", "Linguine sign: wavy low-signal lines of collapsed shell floating in gel", "Popcorn calcification", "Rim enhancement"], "answer_index": 1, "explanation": "Collapsed implant shell floating within silicone inside the intact fibrous capsule produces the classic linguine sign."}, {"q": "A silicone-selective (silicone-only) MRI sequence is designed to suppress:", "options": ["Silicone signal only", "Signal from both fat and water so silicone stays bright", "Only motion", "Gadolinium enhancement"], "answer_index": 1, "explanation": "Suppressing fat and water leaves silicone as the bright signal, making leaks easy to see."}, {"q": "Extracapsular silicone implant rupture is diagnosed when silicone is seen:", "options": ["Inside the shell only", "Between the shell and the capsule only", "Outside the fibrous capsule in breast tissue or lymph nodes", "In the saline fill port"], "answer_index": 2, "explanation": "Extracapsular rupture means silicone has escaped through both the shell and the fibrous capsule into surrounding tissue or nodes."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Nipple and subareolar region", "exam": "Nipple-in-profile view", "image": {"file": "mammography__breast__nipple-in-profile-view.jpg", "caption": "Left MLO mammogram with the nipple shown in profile (labeled).", "credit": "Cerevisae", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Normal_mammography_of_left_breast_in_MLO_view_showing_the_nipple_location.jpg"}, "questions": [{"q": "Why is the nipple shown in profile on at least one view?", "options": ["It lowers the dose to the areola", "It is required for AEC detector placement", "It prevents the paddle from slipping", "So it is not mistaken for a mass and the subareolar tissue can be evaluated"], "answer_index": 3, "explanation": "A nipple not in profile can mimic a retroareolar mass and hide the tissue directly behind it."}, {"q": "The nipple is in profile on this MLO. If profiling the nipple on a routine view would cost posterior tissue, the technologist should:", "options": ["Profile the nipple anyway and accept missed posterior tissue", "Skip the nipple entirely", "Prioritize posterior tissue on the routine view and add a separate nipple-in-profile view if needed", "Use magnification on every view"], "answer_index": 2, "explanation": "Posterior coverage takes priority; the nipple can be shown on a supplemental image."}, {"q": "When the nipple cannot be shown in profile, a small round marker may be placed on it to:", "options": ["Increase contrast", "Identify the nipple so it is not mistaken for a subareolar mass", "Measure compression force", "Block scatter radiation"], "answer_index": 1, "explanation": "A nipple marker shows where the nipple projects, preventing it from being read as a lesion."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Nipple and subareolar region", "exam": "Anterior compression view", "image": null, "questions": [{"q": "When an anterior compression view is taken with AEC, the detector should be:", "options": ["Placed under the thick posterior breast", "Turned off and replaced with fluoroscopy", "Set to maximum mAs", "Positioned under the anterior (subareolar) tissue, or manual technique used"], "answer_index": 3, "explanation": "The exposure must be sampled from the anterior tissue being imaged; sampling posterior tissue would expose it incorrectly."}, {"q": "During an anterior compression view, the posterior breast is:", "options": ["Deliberately left outside the compressed area so pressure is focused on the anterior tissue", "Compressed harder than the anterior breast", "Removed with the paddle tilted backward", "Always included as on a routine CC"], "answer_index": 0, "explanation": "Placing the paddle over only the front of the breast concentrates compression where routine views under-compress."}, {"q": "Which normal structures converge in the subareolar region and are better separated on an anterior compression view?", "options": ["Cooper ligaments of the posterior breast", "Intercostal muscles", "Lactiferous ducts", "Axillary lymph nodes"], "answer_index": 2, "explanation": "The major lactiferous ducts converge behind the nipple; better compression spreads them and the surrounding tissue."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Nipple and subareolar region", "exam": "Spot compression of subareolar area", "image": {"file": "mammography__breast__spot-compression-of-subareolar-area.jpg", "caption": "Focal compression magnification CC image of the retroareolar region showing a circumscribed bilobed nodule.", "credit": "SCiardullo", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:N%C3%B3dulo_BR_3_Magnificaci%C3%B3n_en_incidencia_CC.JPG"}, "questions": [{"q": "This focal compression image of the retroareolar region better shows the nodule because:", "options": ["The grid has been doubled", "Overlapping tissue is spread away, making the margins easier to judge", "Contrast was injected", "The nipple has been removed from the field"], "answer_index": 1, "explanation": "Focal compression thins and spreads the area so a true lesion's shape and margins can be assessed."}, {"q": "Using BI-RADS location terms, a finding directly behind the nipple is described as:", "options": ["Subareolar (retroareolar)", "Axillary tail", "12 o'clock, posterior depth", "Inferomedial"], "answer_index": 0, "explanation": "BI-RADS uses subareolar (retroareolar) and central for findings behind the nipple rather than a clock position."}, {"q": "To confirm that a possible subareolar finding is real, spot compression is usually obtained in at least:", "options": ["One projection", "Two projections (for example CC and ML)", "Four oblique projections", "Only the original view, repeated"], "answer_index": 1, "explanation": "A finding that persists in two projections is likely real and can be localized; a single view cannot exclude summation."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Nipple and subareolar region", "exam": "Breast ultrasound for nipple discharge", "image": {"file": "mammography__breast__breast-ultrasound-for-nipple-discharge.jpg", "caption": "Breast ultrasound: dilated duct containing an intraductal papilloma.", "credit": "Nevit Dilmen", "license": "CC BY-SA 3.0", "page_url": "https://commons.wikimedia.org/wiki/File:Ultrasound_12070I6_intraductal_papilloma_nevit.jpg"}, "questions": [{"q": "Spontaneous, bloody discharge from a single duct of one breast is most often caused by:", "options": ["Galactocele", "Lipoma", "Intraductal papilloma", "Duct ectasia with popcorn calcifications"], "answer_index": 2, "explanation": "Intraductal papilloma is the most common cause of single-duct bloody discharge, though malignancy must be excluded."}, {"q": "This ultrasound shows a dilated duct with an intraductal mass. Which transducer is preferred for this exam?", "options": ["Low-frequency curved array, 2–5 MHz", "Phased array cardiac probe", "Endocavitary probe", "High-frequency linear array, about 12 MHz or more"], "answer_index": 3, "explanation": "Superficial ducts require a high-frequency linear transducer for the best spatial resolution."}, {"q": "To follow the ducts when scanning a patient with nipple discharge, the transducer is best oriented:", "options": ["Radially, along the long axis of the ducts toward the nipple", "Transversely across the sternum", "Only in the sagittal plane at the axilla", "Parallel to the ribs at the chest wall"], "answer_index": 0, "explanation": "Ducts radiate from the nipple like spokes, so radial scanning shows a duct and any intraductal lesion along its length."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Spot compression and magnification (diagnostic work-up)", "exam": "Spot compression view", "image": {"file": "mammography__breast__spot-compression-view.jpg", "caption": "Spot compression view spreading overlapping tissue in a questioned area; no persistent lesion.", "credit": "Cerevisae", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Spot_compression_view_mammography_to_spread_out_breast_tissues_and_visualise_lesion_in_an_area.jpg"}, "questions": [{"q": "What is the main purpose of a spot compression view?", "options": ["To spread overlapping tissue and tell a true lesion from summation of normal tissue", "To show the whole breast at lower dose", "To image the axillary lymph nodes", "To check the compression force for QC"], "answer_index": 0, "explanation": "Focal compression separates superimposed tissue, so pseudo-lesions disappear while real masses persist."}, {"q": "In this spot compression view, the questioned area spreads out and no lesion persists. This most likely means the original finding was:", "options": ["A cancer that needs biopsy", "Superimposition (summation) of normal tissue", "Milk of calcium", "A skin mole"], "answer_index": 1, "explanation": "A density that disperses under focal compression is usually overlapping normal tissue rather than a true mass."}, {"q": "Compared with the standard paddle, the small spot paddle allows:", "options": ["Higher pressure over a small area for better tissue separation", "Lower dose to the whole breast", "Imaging without any compression", "Use of a larger focal spot"], "answer_index": 0, "explanation": "Concentrating force on a small area thins the tissue locally and separates overlapping structures."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Spot compression and magnification (diagnostic work-up)", "exam": "Magnification view (often with spot paddle)", "image": {"file": "mammography__breast__magnification-view-often-with-spot-paddle.jpg", "caption": "Magnification view with a spot paddle, used to assess calcifications and lesion margins.", "credit": "Cerevisae", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Magnification_view_mammography.jpg"}, "questions": [{"q": "Magnification views like this one are most often performed to assess:", "options": ["Skin thickness", "The pectoral muscle", "Lymph nodes in the axilla", "The number, shape and distribution of calcifications and lesion margins"], "answer_index": 3, "explanation": "Magnification improves the visibility of fine detail, helping characterize calcifications and the borders of masses."}, {"q": "For a magnification view, the breast is placed:", "options": ["Directly on the detector as for a contact view", "On a magnification stand that raises it away from the detector, increasing OID", "Under a lead apron", "In the prone biopsy table aperture"], "answer_index": 1, "explanation": "The stand increases object-to-image distance so the image is enlarged."}, {"q": "In BI-RADS, calcifications described as 'grouped' occupy a small area, generally no more than about:", "options": ["1 mm", "5 cm", "2 cm", "One quadrant"], "answer_index": 2, "explanation": "Grouped describes a few calcifications in a small volume, from about 1 cm up to 2 cm; larger areas are regional."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Spot compression and magnification (diagnostic work-up)", "exam": "Rolled views", "image": null, "questions": [{"q": "Rolled views are mainly used to:", "options": ["Image the axillary lymph nodes", "Decide whether a finding seen in one view is real and help localize it", "Reduce compression for patient comfort", "Replace the MLO in screening"], "answer_index": 1, "explanation": "Shifting tissue layers shows whether a density persists (real) or disperses (summation) and indicates which half of the breast holds it."}, {"q": "How is a rolled CC performed?", "options": ["The tube is angled 45°", "The breast is pulled into the axilla", "The top and bottom of the breast are rolled in opposite directions before compression", "The patient is placed prone"], "answer_index": 2, "explanation": "The superior and inferior surfaces are rolled in opposite directions, shifting tissue layers relative to each other."}, {"q": "A rolled CC is labeled RL or RM. The letter after 'R' indicates:", "options": ["The direction the superior tissue was rolled", "The breast imaged", "The radiologist's initials", "The kVp setting"], "answer_index": 0, "explanation": "By convention, RL or RM tells which way the upper (superior) tissue was rolled, which is needed to interpret how a finding moved."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Spot compression and magnification (diagnostic work-up)", "exam": "Targeted breast ultrasound", "image": {"file": "mammography__breast__targeted-breast-ultrasound.jpg", "caption": "Targeted breast ultrasound of an oval hypoechoic nodule with calipers measuring two dimensions.", "credit": "SCiardullo", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Nodulos_BR3_-_Ecografia.JPG"}, "questions": [{"q": "This targeted ultrasound shows an oval hypoechoic nodule that is wider than tall. A parallel ('wider-than-tall') orientation generally:", "options": ["Favors a benign process", "Proves malignancy", "Means the lesion is a cyst", "Has no value"], "answer_index": 0, "explanation": "Parallel orientation is a benign-leaning feature; a taller-than-wide (non-parallel) orientation raises suspicion."}, {"q": "Which set of information should be documented for a lesion found on targeted breast ultrasound?", "options": ["Only the date of the exam", "Breast side, clock position, distance from the nipple, and transducer orientation", "Patient weight and height", "Mammography kVp"], "answer_index": 1, "explanation": "Laterality, clock face, distance from the nipple and probe orientation let the finding be found again and correlated."}, {"q": "A targeted ultrasound is done for a mammographic mass. The sonographic finding is accepted as the same lesion when:", "options": ["It is in the opposite breast", "It is larger than 5 cm", "Its location, depth, size and shape match the mammographic finding", "It is anechoic regardless of location"], "answer_index": 2, "explanation": "Correlation requires matching position, depth, size and shape; otherwise the mammographic finding may not have been found."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Skin lesions and tangential (TAN) views", "exam": "Tangential view", "image": null, "questions": [{"q": "What does a tangential view accomplish for a suspected skin lesion or skin calcifications?", "options": ["It magnifies the lesion two times", "It removes the lesion from the image completely", "It projects the finding into the subcutaneous fat to confirm it is in the skin", "It places the finding at the chest wall"], "answer_index": 2, "explanation": "Aiming the beam tangent to the skin at the finding shows whether it lies in the skin rather than in the breast tissue."}, {"q": "Before obtaining a tangential view of a possible skin lesion, the technologist usually:", "options": ["Marks the lesion site on the skin, often using a localization grid, then positions the beam tangent to the skin at that point", "Injects contrast into the lesion", "Removes all compression", "Takes a 90° lateral first"], "answer_index": 0, "explanation": "Locating and marking the lesion lets the breast be turned so the beam skims the skin at that spot, projecting the finding into the subcutaneous fat."}, {"q": "A tangential view of a palpable lump in a dense breast can help because it:", "options": ["Increases dose to the lump", "Projects the lump over subcutaneous fat, where it is easier to see", "Hides overlying tissue with lead", "Removes the need for ultrasound"], "answer_index": 1, "explanation": "Placing the lump against fat rather than dense tissue improves its visibility on the image."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Skin lesions and tangential (TAN) views", "exam": "Skin marker placement (moles, scars, palpable lumps)", "image": {"file": "mammography__breast__skin-marker-placement-moles-scars-palpable-lumps.jpg", "caption": "Mammogram with a radiopaque lump marker placed on the skin over a palpable area (labeled).", "credit": "Cerevisae", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Lump_marker_mammography.jpg"}, "questions": [{"q": "This image shows a marker placed over a palpable area. Why are different marker shapes used for lumps, moles and scars?", "options": ["They have different radiation doses", "So the radiologist can tell what each marked finding represents", "Shapes are chosen at random", "Only lumps need markers"], "answer_index": 1, "explanation": "Distinct markers (e.g., a BB for a lump, a ring for a mole, a line for a scar) communicate what the technologist marked."}, {"q": "An unmarked raised skin mole on a mammogram may be mistaken for:", "options": ["A lymph node in the axilla", "An implant", "A mass or calcification within the breast", "The pectoral muscle"], "answer_index": 2, "explanation": "Raised skin lesions surrounded by air can project over the breast and mimic an intramammary mass."}, {"q": "When should skin markers be applied?", "options": ["Before positioning, after inspecting the skin and taking the patient's history", "After the exam is read", "Only if the radiologist requests a recall", "Only on the MLO"], "answer_index": 0, "explanation": "Markers go on at the start so every image shows them, which requires examining the skin and asking about lumps and surgery first."}]}, {"modality": "Mammography", "region": "breast", "region_label": "Skin lesions and tangential (TAN) views", "exam": "CC and MLO with markers", "image": {"file": "mammography__breast__cc-and-mlo-with-markers.jpg", "caption": "Right CC and MLO views with linear scar markers on the skin (labeled).", "credit": "Cerevisae", "license": "CC BY-SA 4.0", "page_url": "https://commons.wikimedia.org/wiki/File:Scar_marker_as_seen_on_MLO_and_CC_view_on_mammography.png"}, "questions": [{"q": "A linear radiopaque skin marker on a mammogram typically indicates:", "options": ["A palpable lump", "The nipple", "A mole", "A surgical scar"], "answer_index": 3, "explanation": "Linear markers are placed along scars so post-surgical distortion is not misread as a suspicious finding."}, {"q": "These CC and MLO images show linear scar markers. Why is a surgical scar marked?", "options": ["To lower the exposure", "So post-surgical distortion at the scar is not mistaken for a new cancer", "To help AEC", "To mark the nipple"], "answer_index": 1, "explanation": "Linking architectural distortion to a skin scar lets the radiologist recognize expected post-surgical change."}, {"q": "Years after a lumpectomy, which change at the marked scar site is most concerning?", "options": ["Increasing density or new calcifications at the site", "Stable distortion", "Decreasing skin thickening", "Stable dystrophic calcification"], "answer_index": 0, "explanation": "Post-surgical changes should be stable or improve; a growing density or new calcifications at the site raise concern for recurrence."}]}]