Archived Case 31

1. Work-up of extent of disease of a known breast cancer, when the extent is in question on the mammogram or ultrasound, or if the patient is status post lumpectomy with positive margins.

2. Axillary metastases with unknown primary and negative mammogram and ultrasound

3. Evaluate for silicone implant rupture

The indications for MRI are growing, and have been somewhat controversial. Possible other indications for MR:

1. Problem-solving when mammogram and/or ultrasound are indeterminate

2. Screening for high-risk women

Having dense breasts is not an indication for MRI. The cost of screening average risk women with dense breasts would be prohibitive. Perhaps one day when MRI is more affordable this will come into vogue

The patient went on to have lumpectomy and radiation, and is doing well.

It is obviously unfair to ask you to assess an MRI from 2 images when I had the advantage of looking at all 1500 images! A full discussion of MR imaging is beyond the scope of this teaching case (stay tuned for a new MRI teaching set), but it is common to see scattered stippled progressive (increasing on time curves) enhancement or small 2-3 mm foci of progressive enhancement in benign tissue. If this is a diffuse bilateral and symmetric pattern, it, like a similar pattern with calcifications, is considered benign.

Masses with irregular or spiculated margins, heterogeneous enhancement, irregular rim enhancement, and washout on delayed images are suspicious for malignancy.