Ah, a perfect question for comparative effectiveness research.
Surgeon Jeffrey Parks takes a look at a study looking at breast MRIs during the pre-operative workup of patients with breast cancer.
Essentially, surgical outcomes were not improved, and worse, “leads to a higher rate of unnecessary mastectomy, and is extremely expensive (about $1600 a pop, out of pocket).”
Although there are specific cases where a breast MRI may be indicated, it is questionable whether it adds more useful information over a mammogram alone in most cases.
I agree with Dr. Parks (emphasis mine), in that “there is not nearly enough evidence to support its routine use in most patients with breast cancer.”