If you are crunched for time, do not waste time by looking up radiology stuff. Often you can figure out the answer without having "knowledge" of reading the radiographs. And this is REALLY LOW YIELD. Keep in mind that people mention the stuff they are most unfamiliar with on these boards...the 2-3 questions out of 300 people (it may SEEM like more than that) get with radiology may stick out, but is hardly worth the time to study when compared to the "core areas" (path, physio, anat, biochem, pharm, etc.).