@debdeb1 , I recently went through the stress of an abnormal test on my remaining breast, after a mastectomy to the other breast one year ago. In the past I was never stressed about being called back for additional images, but this time I was concerned. So, I understand the anxiety that goes along with what you are facing.
I have had all three types of biopsies. The ultrasound biopsy was the easiest for me. My guess is that your doctor was hoping that they could see the spot on ultrasound, so they could do the US guided biopsy. Because they confirmed that they can only see this spot on an MRI, they want to use that modality to do the biopsy. For me, MRI was the least comfortable type of breast biopsy, just because of the position that you are in for the procedure. Some people may tolerate it better than others, and my clinic was very good about trying to keep me comfortable during the procedure.
https://www.mayoclinic.org/tests-procedures/breast-biopsy/about/pac-20384812
The radiologists determined that my spot was an overly dense area of tissue. Nothing to worry about. I'll be scanned again in 6 months.
Please let us know how it goes for you.