First of all, every program will screen based on some preliminary cut off point for USMLE step I, but that cut off point will be different for every program based on their profile of desired candidates who are likely to rank them high on the rank list.
Top tier programs (there is no official ranking for these programs, but these programs tend to be associated with large, research oriented universities) tend to like research, and MD-PhD's have a lot of success at these programs; they also like AOA and Step I scores >230. Not every candidate they accept will have these credentials -- knowing someone in the program who thinks well and highly of you will go a long way; also, MD-PhD's get a break for the extra credentials and experience.
Middle tier programs include smaller universities with less research, larger community programs with affiliations with more prestigious institutions, any small to medium size program in California (everyone wants to live in Calif, and even programs that aren't that good get stellar candidates). They tend to like Step I >215-225; again, MD-PhDs and people they already know and like get breaks. Interviews count for a lot since the majority of people who are applying will fall in this range, and the only way to stand out is how they present in person.
DO, US citizen FMGs, and noncitizen FMGs all have disadvantages in that order. But many of the more outstanding candidates can still get into rads, including at many middle tier program. Again, good step I, research, good subinternship evaluations/impressions, letters, etc help tremendously.
If I sound repetitive, that's good. The more/better your credentials, the better your chances. If you are an average, mediocre, or less than average applicant, then you need to be flexible about location and pestige of the program you are applying to.
Thanks.
