That is confusing. I'm thinking the only difference between a regular and diagnostic mammogram is one is routine on the breast that never had issues and the diagnostic is just a followup on the one that had issues. Sounds like the same test, but more of an insurance coverage issue. I only had cancer in one breast, yet for 10 years since my mastectomy I have always had ultrasounds and MRIs on both sides of my chest at the same time. Don't hesitate to ask your team for more of an explanation. Best of luck to you.