Dear kimbie: MRI is sometimes used in conjunction with other testing to provide additional information that will help the radiologist. Because you went to the surgeon initially, you have had a surgical consultation. You may want to contact your surgeon and explain your confusion and see if he can answer your questions. Without reviewing the ultrasound and doing an examination, we cannot speculate on what our recommendations would be.
I also have BC with double masectomy and reconstruction. I have MRI's to watch spots that they feel are not cancer. I do not mind having them because it makes me feel better checking out things. I agree that you need to talk with your doctor. I have been trying to get more involved. My doctors have been showing me the ultasound, MRI and PET scan results - they point out what they question. You might try to go back and talk with him and look at what they are questioning. I really believe that you need to know just as much as what is happening as your team of doctors.
You might also ask why he thinks it's not cancer. Is it a clear cysts (not cancer) or a solid lump (could be cancer). You might also ask if this spot is pre-cancerous? Could it turn into cancer? Do you need other tests, PET scan is a good but expensive tests that shows hot spots (cancer or infections) that might also help in understanding your body. Be prepared with questions and talk with both groups that you seen.
Good luck.