Dynamic contrast-enhanced MR imaging in screening detected microcalcification lesions of the breast: is there any value?

PURPOSE

To prospectively evaluate whether dynamic contrast-enhanced magnetic resonance (MR) imaging findings can help predict the presence of malignancy when screening detected microcalcification lesions, and its contribution to patient management of stereotactic vacuum-assisted breast biopsy (SVAB).

MATERIALS AND METHODS

Dynamic contrast-enhanced breast MR imaging was performed when screening 100 detected microcalcification lesions not visualized by ultrasonography with 11-gauge SVAB. Definitive surgery was performed on all patients with the biopsy resulting in the diagnosis of breast cancer or atypical ductal hyperplasia (ADH). Positive predictive values (PPVs) and negative predictive values (NPVs) were calculated on the basis of a BI-RADS (Breast Imaging Reporting and Data System) category and the absence or presence of contrast uptake in the area of microcalcification.

RESULTS

The BI-RADS mammography category correlated with the diagnosis of breast cancer (ADH excluded): category 3 = 7% (4/55); category 4 = 48% (13/27); category 5 = 94% (17/18). After dynamic contrast-enhanced MR imaging, three of four malignancies with BI-RADS mammography category 3 were diagnosed as true positive. Therefore, the PPV of BI-RADS mammography category 3 with MR imaging was 1.8% (1/55). The PPV of contrast uptake of MR imaging was 86% (32/37), significantly higher than the 67% (30/45) PPV of BI-RADS mammography 4 and 5 (P = 0.033). The NPV of BI-RADS mammography 3 was 93% (51/55) versus 97% (61/63) NPV of MR imaging (P = 0.167).

CONCLUSION

In the evaluation of screening detected microcalcification lesions, dynamic contrast-enhanced breast MR imaging provides additional information with high PPV and NPV, and may therefore offer an alternative to SVAB for women who do not want to undergo SVAB with equivocal findings following full diagnostic mammographic assessment, but breast MR imaging with imperfect PPV and NPV cannot replace SVAB.

CLINICAL RELEVANCE

Dynamic contrast-enhanced breast MR imaging can demonstrate malignant microcalcifications detected by screening mammography and can be recommended in the evaluation of equivocal microcalcifications prior to SVAB.