Breast magnetic resonance imaging (MRI) has attained a solid position in the evaluation of the breast, and many believe it is currently a necessary component of any breast imaging practice. In the past decade, many advances have contributed to the more routine use of this robust tool for cancer detection, including newer faster imaging sequences with improved image quality as well as new biopsy equipment that allows percutaneous needle biopsy of suspicious lesions. Additionally, societies have created guidelines for breast MRI, thus improving standardization in the performance, interpretation, and recommended use of this technology. Many of our current algorithms in the detection and treatment of breast cancer have been changed by the availability of breast MRI.
Clinical indications for breast MRI1 include screening for breast cancer in the high-risk patient (Fig. 35-1), assessing response to chemotherapy in the patient with known breast cancer undergoing new-adjuvant chemotherapy (Fig. 35-2), assessing residual disease in a conserved breast with positive margins (Fig. 35-3), assessing possible recurrence in the treated breast when there is clinical or imaging suspicion (Fig. 35-4), screening the contralateral breast in the patient with known breast cancer (Fig. 35-5), and assessing for underlying cancer in a patient with occult primary breast cancer (Fig. 35-6). Breast MRI can also be valuable in the evaluation of inconclusive findings on conventional imaging (Fig. 35-7). The final clinical indication where MRI may be helpful but where there is less clinical evidence is assessing extent of disease in the preoperative setting (Fig. 35-8).
High-risk screening. A 37-year-old high-risk woman with suspicious rim enhancing mass with surrounding clumped enhancement in the posterior breast that proved to represent a 4-mm invasive carcinoma with surrounding ductal carcinoma in situ.
Response to chemotherapy. A 37-year-old woman with recent diagnosis of left breast and left axillary nodal metastases. (A) Pre- and (B) post-neoadjuvant chemotherapy.
Residual disease assessment. Postoperative magnetic resonance imaging was performed for widely positive margins a few days following surgery. A seroma cavity is identified in the central breast with an air-fluid layer (the patient is scanned prone). Along the posterior aspect of the seroma cavity toward the chest wall, there is lobular enhancement that represents residual disease. The amount of residual disease proved too much for reexcision (proved first by percutaneous biopsy), and the patient underwent mastectomy.
Recurrence following breast conservation. A 63-year-old woman with a history of ductal carcinoma in situ in the posterior breast (lumpectomy site clips are visible as black ...