Breast MRI documenting response to neoadjuvant chemotherapy

Breast MRI can be used to document the response to neoadjuvant chemotherapy. This series illustrates the response to chemotherapy in a patient with a palpable right breast mass and nipple inversion. Mammography and ultrasound confirmed a large irregular mass and biopsy showed invasive lobular carcinoma. The patient was treated with neoadjuvant chemotherapy. MRI prior to therapy showed a large irregular mass extending from the nipple and involving the upper and central breast (A, arrow). Post-treatment MRI showed a partial response and scattered foci suggestive of residual disease (B, arrow). Subtraction of imaging prior to and after contrast administration highlights enhancing tissue which has been labeled as substracted post.