Have you ever wondered where you doctors are getting the guidelines for interpretation of your exams? They are not pulling random numbers and studies out of the sky. In fact, many of the radiologists I have worked with refer to http://www.acr.org, American College of Radiology, for the appropriateness criteria.
This website does require membership to fully access the criteria and guidelines. The information is evidence based with plenty of clinical studies to validate follow up and treatment. It is an amazing resource and I have barely scratched the surface here. One of the most impressive things about this is the ability to site published scientific papers for evidence based criteria. Amazing!!!! It looks like I will have enough reading to keep me entertained for many years to come if I really want to dig into it!