Radiographic Imaging and Angiography
Core concepts
Angiography questions test image acquisition, projection selection, contrast handling, and recognition of normal versus abnormal findings. Understand fluoroscopy basics: kVp and mA settings, pulse rate, collimation, and the ALARA principle. Know standard projections-LAO cranial and caudal, RAO cranial and caudal, and AP-and which projection best opens which coronary segment. The LAO cranial view typically elongates the LAD; RAO caudal often opens the circumflex; LAO caudal (spider) shows the left main bifurcation.
Know contrast properties: iodine-based agents are radiopaque; osmolality and volume affect nephrotoxicity and patient comfort. Recognize angiographic lesion features: percent diameter stenosis, TIMI flow grade (0 = no flow, 3 = normal), thrombus, dissection, and calcification.
Understand ventriculography for ejection fraction and wall motion, and the role of fractional flow reserve and intravascular imaging when indicated. Radiation safety is integral: minimize time, maximize distance, use shielding, and collimate.
Traps
Questions confuse which projection best demonstrates a segment, or misstate TIMI grades. Remember TIMI 3 is normal flow, not TIMI 1. Do not equate percent stenosis with physiologic significance-anatomy and physiology can diverge. Watch for questions about contrast volume limits in renal impairment.
Rule of thumb
For projection questions, recall that cranial angulation opens the LAD and caudal angulation opens the circumflex; the spider view shows the left main. For flow, memorize TIMI 0–3 in order.