3-T breast magnetic resonance imaging in patients with suspicious microcalcifications on mammography

OBJECTIVE: To investigate the diagnostic value of 3-Tesla (T) breast MRI in patients presenting with microcalcifications on mammography.

METHODS: Between January 2006 and May 2009, 123 patients with mammographically detected BI-RADS 3–5 microcalcifications underwent 3-T breast MRI before undergoing breast biopsy. All MRIs of the histopathologically confirmed index lesions were reviewed by two breast radiologists. The detection rate of invasive carcinoma and ductal carcinoma in situ (DCIS) was evaluated, as well as the added diagnostic value of MRI over mammography and breast ultrasound.

RESULTS: At pathology, 40/123 (33%) lesions proved malignant; 28 (70%) DCIS and 12 (30%) invasive carcinoma. Both observers detected all invasive malignancies at MRI, as well as 79% (observer 1) and 86% (observer 2) of in situ lesions. MRI in addition to conventional imaging led to a significant increase in area under the receiver operating characteristic (ROC) curve from 0.67 (95% CI 0.56–0.79) to 0.79 (95% CI 0.70–0.88, observer 1) and to 0.80 (95% CI 0.71–0.89, observer 2), respectively.

CONCLUSIONS: 3-T breast MRI was shown to add significant value to conventional imaging in patients presenting with suspicious microcalcifications on mammography.

KEY POINTS: • 3-T MRI is increasingly used for breast imaging in clinical practice. • On 3-T breast MRI up to 86% of DCIS lesions are detected. • 3-T MRI increases the diagnostic value in patients with mammographically detected microcalcifications.