{
"id": "radiography-procedures",
"modality": "Radiography",
"category": "Procedures",
"title": "Radiography Procedures: Positioning Essentials",
"minutes": 9,
"slides": [
{
"id": 1,
"diagram": "title",
"heading": "Radiography Procedures",
"bullets": [
"66 of 200 scored questions (33%)",
"Terms, chest, abdomen and GI studies",
"Skull, spine, pelvis and hip",
"Upper and lower extremity must-knows"
],
"narration": "Welcome to Radiography Procedures. This is the biggest category on the radiography boards: 66 of the 200 scored questions, or 33 percent. We'll start with positioning terms and the chest, then the abdomen and contrast studies of the gastrointestinal tract. After that we'll hit the skull, spine, pelvis and hip, where angles and obliques get tested hard. We'll finish with the upper and lower extremity must-knows: the special views, rotations and central ray angles that show up again and again. Let's go.",
"svg": ""
},
{
"id": 2,
"diagram": "decubitus",
"heading": "Positioning terms",
"bullets": [
"Projection = path of the central ray (AP, PA)",
"Decubitus = lying down with a horizontal beam",
"Decubitus is named for the side down",
"Obliques are named for the side closest to the IR"
],
"narration": "Terminology questions are free points if you know the rules. A projection is the path of the central ray, like anterior posterior, A P, or posterior anterior, P A. A position describes the patient's body. Decubitus always means lying down with a horizontal beam, and it's named for the side down, so left lateral decubitus means left side down. Obliques are named for the side closest to the image receptor. Left posterior oblique, L P O, means the left back is against the receptor.",
"svg": ""
},
{
"id": 3,
"diagram": "pa-chest",
"heading": "Chest essentials",
"bullets": [
"PA erect at 72 in SID to reduce heart magnification",
"Full inspiration: at least 10 posterior ribs",
"Left lateral puts the heart closer to the IR",
"Decubitus: fluid side down, free air side up"
],
"narration": "The chest is the most common exam you'll do. Shoot it P A and erect at a 72 inch source to image distance to reduce heart magnification and show air-fluid levels. On full inspiration, take the exposure on the second breath, and you should see at least 10 posterior ribs above the diaphragm. The routine lateral is a left lateral, which puts the heart closer to the receptor. For decubitus chests, remember fluid falls and air rises: fluid side down, free air side up.",
"svg": ""
},
{
"id": 4,
"diagram": "gi-obliques",
"heading": "Abdomen and GI studies",
"bullets": [
"KUB: CR at iliac crest, exposed on expiration",
"Free air: erect chest or left lateral decubitus",
"UGI: RAO and right lateral fill the bulb with barium",
"BE: posterior oblique opens the up-side flexure"
],
"narration": "For a K U B, meaning kidneys, ureters and bladder, center at the iliac crest and expose on expiration. For free air, the best views are an erect chest or a left lateral decubitus abdomen, where air rises over the liver. In the upper G I, barium goes to the dependent part, so R A O and right lateral fill the duodenal bulb with barium, while L P O puts air in the bulb. On a barium enema, posterior obliques open the flexure on the side up, so L P O shows the hepatic flexure.",
"svg": ""
},
{
"id": 5,
"diagram": "skull-lines",
"heading": "Skull and facial bones",
"bullets": [
"OML and IOML differ by about 7 degrees",
"Towne: 30 degrees caudal to OML",
"Caldwell: 15 degrees caudal to OML",
"Waters: OML 37 degrees to IR; modified Waters 55"
],
"narration": "Skull angles live and die by the baselines. The orbitomeatal line, O M L, and the infraorbitomeatal line, I O M L, differ by about 7 degrees. The A P axial, or Towne, uses 30 degrees caudal to the O M L, or 37 to the I O M L, and shows the dorsum sellae in the foramen magnum. The P A axial Caldwell uses 15 degrees caudal to the O M L. For facial bones, the Waters puts the O M L at 37 degrees to the receptor, and the modified Waters at 55 degrees for the orbital floors.",
"svg": ""
},
{
"id": 6,
"diagram": "spine-obliques",
"heading": "Spine obliques and laterals",
"bullets": [
"C-spine anterior oblique: foramina closest to the IR",
"Lateral C-spine at 72 in SID; must include C7-T1",
"Lumbar posterior oblique: joints closest to the IR",
"Scottie dog neck = pars interarticularis"
],
"narration": "Spine obliques are a classic trap because the rules flip. On the cervical spine, obliques show the intervertebral foramina, and an anterior oblique shows the foramina closest to the receptor, while a posterior oblique shows the side farthest away. Shoot the lateral cervical spine at 72 inches and always include C7 to T1, using a swimmer's view if needed. On the lumbar spine, obliques show the zygapophyseal joints, and a posterior oblique shows the joints closest to the receptor. On the Scottie dog, the neck is the pars interarticularis, where spondylolysis breaks.",
"svg": ""
},
{
"id": 7,
"diagram": "pelvis-rotation",
"heading": "Pelvis and hip",
"bullets": [
"AP pelvis: feet internally rotated 15-20 degrees",
"Suspected hip fracture: do not rotate the leg",
"Trauma lateral hip: cross-table (Danelius-Miller)",
"Frog-leg is never used for suspected fracture"
],
"narration": "For an A P pelvis, rotate the feet internally 15 to 20 degrees so the femoral necks lie parallel to the receptor and the lesser trochanters barely show. But if a hip fracture is suspected, with a shortened, externally rotated leg, do not rotate the leg; image it as it lies. The trauma lateral is the cross-table axiolateral, called the Danelius-Miller, with the good leg raised. The frog-leg lateral is never used when a fracture is suspected.",
"svg": ""
},
{
"id": 8,
"diagram": "upper-extremity",
"heading": "Upper extremity",
"bullets": [
"Scaphoid: PA with ulnar deviation",
"Elbow medial oblique: coronoid process",
"Elbow lateral oblique: radial head and neck",
"Scapular Y for shoulder dislocation",
"AP forearm: hand supinated so bones don't cross"
],
"narration": "Upper extremity questions pair a part with its special view. For the scaphoid, the most often fractured carpal, use a P A with ulnar deviation. At the elbow, the medial oblique shows the coronoid process, and the lateral oblique frees the radial head and neck from the ulna. For a shoulder dislocation, the scapular Y view shows the humeral head in relation to the glenoid; an anterior dislocation sits under the coracoid. And for an A P forearm, supinate the hand, because pronating it crosses the radius over the ulna.",
"svg": ""
},
{
"id": 9,
"diagram": "lower-extremity",
"heading": "Lower extremity",
"bullets": [
"AP foot: CR 10 degrees toward the heel",
"Medial oblique foot opens the cuboid",
"Mortise: leg rotated 15-20 degrees internally",
"Lateral knee: flexed 20-30, CR 5-7 degrees cephalic",
"Medial oblique knee opens the proximal tib-fib joint"
],
"narration": "On the lower extremity, angles and rotations rule. The A P foot uses a central ray angled 10 degrees toward the heel, perpendicular to the metatarsals. The medial oblique foot opens the cuboid and lateral tarsals. For the ankle mortise, rotate the leg 15 to 20 degrees internally until the intermalleolar line is parallel to the receptor. A lateral knee is flexed 20 to 30 degrees with the central ray 5 to 7 degrees cephalic to superimpose the condyles. And the medial oblique knee opens the proximal tibiofibular joint.",
"svg": ""
},
{
"id": 10,
"diagram": "summary",
"heading": "Lock these in",
"bullets": [
"Decubitus: horizontal beam, named for side down",
"Chest: 72 in, PA erect, 10 posterior ribs, left lateral",
"UGI RAO = barium in bulb; LPO = air in bulb",
"C-spine anterior oblique = foramina closest to IR",
"Scaphoid ulnar deviation; coronoid medial oblique"
],
"narration": "Let's lock it in. Decubitus means a horizontal beam, named for the side down. The chest is 72 inches, P A erect, at least 10 posterior ribs, with a left lateral. In the upper G I, R A O puts barium in the duodenal bulb and L P O puts air there. On the cervical spine, an anterior oblique shows the foramina closest to the receptor, the reverse of the lumbar rule. And at the wrist and elbow, scaphoid gets ulnar deviation and the coronoid gets a medial oblique. You've got this.",
"svg": ""
}
]
}