I usually do not defend doctors but in our case urologist told my husband (while he was on AS and PSA 4) that he would benefit from further evaluation. My husband asked what would be better, MRI or biopsy and doctor explained that MRI as a first step is better since it will examine the whole gland and biopsy without MRI would be just random sampling BUT that insurance does not cover MRI as the first step but covers a biopsy. My husband than payed MRI out of pocket and it did show small lesion.
So, it might be that insurance coverage plays a role in what doctor would suggest. Just a thought, maybe I am wrong.