MR Imaging for Diagnosis of Malignancy in Mammographic Microcalcifications: A Systematic Review and Meta-Analysis.

Purpose To assess the use of magnetic resonance (MR) imaging for diagnosis of malignancy in lesions that manifest as microcalcifications at mammography. Materials and Methods Two independent readers performed a systematic review of the literature published as of February 1, 2016, by using predefined search terms. All studies in which contrast material-enhanced MR imaging was used for assessment of mammographic microcalcifications that were assigned Breast Imaging Reporting and Data System (BI-RADS) scores of 3-5 were deemed eligible. The standard of reference was established at clinical follow-up examination or histopathologic evaluation. Study design, technical parameters, number of true- and false-positive and true- and false-negative results were extracted to fit a cross-tabulation. Quality Assessment of Diagnostic Accuracy Studies-2 applet was used to probe for bias. Statistical analysis included data pooling, meta-regression, heterogeneity testing, and forest plot construction. Results Twenty studies met the inclusion criteria. These comprised 1843 lesions with a mean prevalence of malignancy of 40.6%. Bivariate analysis revealed pooled sensitivity and specificity of 87% (95% confidence interval [CI]: 81%, 92%) and 81% (95% CI: 75%, 86%) for all lesions, respectively; 95% (95% CI: 91%, 98%) and 61% (95% CI: 52%, 69%) for invasive lesions only, respectively; 57% (95% CI: 59%, 81%) and 32% (95% CI: 15%, 92%) for BI-RADS 3 lesions, respectively; 92% (95% CI: 85%, 96%) and 82% (95% CI: 74%, 88%) for BI-RADS 4 lesions, respectively; and 95% (95% CI: 87%, 99%) and 66% (95% CI: 26%, 92%) for BI-RADS 5 lesions. Diagnostic criteria other than presence of enhancement were inversely associated with sensitivity (P ≤ .013). Conclusion Breast MR imaging is not recommended for diagnosis of malignancy in BI-RADS 3 and 5 mammographic microcalcifications, but can be considered for BI-RADS 4 mammographic microcalcifications. The presence or absence of enhancement is the preferable diagnostic criterion to rule out malignancy in mammographic microcalcifications at breast MR imaging. © RSNA, 2016 Online supplemental material is available for this article.