My whole last semester is review, which is good because I haven't thought about Compton scatter and the like since we first learned the material almost a year and a half ago. Our school has provided us with an online account that allows us to take practice tests that are set up just like the registry exam.
We can control how many questions there are on each test as well as which subcategories they come from (e.g. patient care, positioning & procedures, physics, techniques, etc.). It has been extremely helpful in studying for the Registry exam. I don't feel ready to take it yet, but I will soon. I just need to keep studying. Speaking of that, I better get to it. It seems to help if I take 1 or 2 30-question practice tests each night when I get home from clinicals. That way I've gone thru a large number of questions in a fairly short amount of time. Works for me!!