Projects 1.AMSA Radiology Interest Group or Radiology Resident e-mail listserv. 2.Contrast Reactions and Creatinine Clearance 3.Vague statistics in radiology reports: rare, unlikely, likely, probably, relate with more clear numbers for how common? Once a day, once a month, once a year, once a career… 4.Internet Journal Club 5.Radiology Decision Support
General Approach to Imaging Have a differential diagnosis before you look at any images Look at one organ at a time. Look at tissue of interest Is this image limited or the wrong modality? What would it look like on ct, us, mri, nucs Compare with normals and internet pictures if confused.
Fractures Ask mechanism of injury and region of focal pain If it looks abnormal: its usually either a limited view, fracture, or both. Limited views (no rotation views) may be because fracture or injury limits mobility. Look at bones individually. Lower threshold for getting ct of pelvis, midfoot, spine, face
Fluoro Ted’s cheat sheet, w&w protocols.Ted’s cheat sheet When Single contrast? –<12 years old –Old >70, limited mobility –Ruleout obstruction or known anatomic defect Why scout? Obstruction, poop, barium, stones, pregnancy, free air. Bronch, Hystero, etc: get angled views Male vcug, get urethra views frontal and lateral Esophageal perforation: ct with esophocat contrast Bladder perforation: ct with 200cc contrast through foley.
CT Windows: named after tissue that is gray and has best contrast (some of it is brighter and some darker than gray). Inflammation: fat gets whiter with edema and hyperemia. Walls get thicker with edema. Abscess: air, central necrosis, peripheral enhancement, reactive lymph nodes. Vascular organs are denser and enhance more. Tumors are usually neo (hypervascular) Hematoma: heterogenous (layering / hematocrit effect) Fat anywhere, water in csf spaces or bladder, air and contrast in bowel are your friend. If you don’t see them, you have a limited exam or pathology.
CT Head Ischemia windows: look at basal ganglia, insular ribbon (temporal lobe), cortex Subdural window: look at quadrigeminal plate cistern, tentorium, csf Soft tissue: look at scalp, sinuses Bone: look at orbits, nose, zygoma, lytic lesions, fracture if scalp swelling. Only subtle finding to really worry about is hemorrage.
IV Contrast See http://www.svhrad.com/CallGuide/OnCall.htm for article on contrast allergy. Contrast timing: –PE, AAA, Dissection PE: pulmonary artery must be whiter than aorta. AAA: without contrast to see crescent sign. Dissection: with contrast to see flap Abdomen: get 3.2mm cuts if no contrast IV or oral or can’t see what’s going on.
MRI http://www.radiology.residentmanual.com/index.php/MRI_protocols Water and pathology: White on T2, dark on T1 and FLAIR Fat: white on T1 and T2, dark on STIR and out of phase Bone Marrow: normally fatty (white on t1), replaced with edema or other pathology (dark on T1) Axons: fatty Gray matter infarct: opposite of csf on DWI and ADC. Bone cortex, stones, and ligaments: dark on everything. Contusion is white Tumor: hypervascular (neovascularity): white with gadolinium Liver, Kidney, adrenals, Pancreas: tumor patterns, just look up in brant and helms or mri book.
Nuclear Medicine V/Q scan: if not clearly normal or high prob, look for artifacts or matched defects. –pioped criteriapioped criteri Bone Scan: if new abnormal uptake spine get obliques (to localize) Others get laterals X-ray or ct to confirm probably benign fx, djd Mri for cancer Don’t bother asking anyone other than bader, mukai, bertrand, chen, gupta for help.