What Is An MRI?

What Is An MRI?

December 14, 2021
Everett Bonner, MD
Everett Bonner, MD

Breast Surgery



So, after your breast surgeon or surgeon has done his clinical exam, reviewed your pathology, then we start formulating the plan. One of the big questions most of my patients will ask is, “Do I need more studies? Do I need an MRI? Do I need a PET scan?” Well, let’s break that down.


MRIs are very new, being around 5, 10 years or so, but it’s becoming more mainstream with the diagnosis and the treatment plans for breast cancer. MRIs have a very specific place within the breast algorithm. Mostly, when I decide and when most people in my position decide, evidence shows that MRIs are good for patients who have lobular carcinoma, because a lot of times lobular carcinoma is the extent of it. It’s not evident on standard imaging, which is mammograms or ultrasounds. MRI lets us know, is there more to the disease than what we’re seeing on some of the standard imaging? Because that has a lot to do with what we recommend from a surgery standpoint. Is this patient a candidate for breast conservative therapy, which is lumpectomy, or do we need to move on to a mastectomy?


Because the disease is more extensive than we initially found on standard imaging. The MRI helps with that. We also look at MRIs in the case of what we call an occult malignancy. That term is used where we feel lymph nodes, but we have normal mammograms and we biopsy those lymph nodes and that patient actually has breast cancer, but we can’t actually see it on mammogram or ultrasound. So those patients will move on to an MRI.


We also use MRIs if we know there is a larger tumor, lymph nodes that are positive and that patient is going to get chemotherapy on the front end, which we call neoadjuvant chemotherapy. Then we do a pre-treatment MRI so that at the end of their treatment, they’ll get another MRI to see how well they responded to that chemotherapy.


Key Takeaways

1. An MRI lets us know if there is more to the disease and helps recommendations for surgery.

2. MRIs are used for occult malignancy, which is where a patient actually has a breast cancer, but can’t be seen on mammogram or ultrasound.

3. MRIs also see if there is a larger tumor, lymph nodes that are positive.

4. An MRI is done before and after chemotherapy to see how well they responded.