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.

ObjectivesTo evaluate the performance of MRI for diagnosis of breast cancer in non-calcified equivocal breast findings.Materials and MethodsWe performed a systematic review and meta-analysis of peer-reviewed studies in PubMed from 01/01/1986 until 06/15/2015. Eligible were studies applying dynamic contrast-enhanced breast MRI as an adjunct to conventional imaging (mammography, ultrasound) to clarify equivocal findings without microcalcifications. Reference standard for MRI findings had to be established by histopathological sampling or imaging follow-up of at least 12 months. Number of true or false positives and negatives and other characteristics were extracted, and possible bias was determined using the QUADAS-2 applet. Statistical analyses included data pooling and heterogeneity testing.ResultsFourteen out of 514 studies comprising 2,316 lesions met our inclusion criteria. Pooled diagnostic parameters were: sensitivity (99%, 95%-CI: 93–100%), specificity (89%, 95%-CI: 85–92%), PPV (56%, 95%-CI: 42–70%) and NPV (100%, 95%-CI: 99–100%). These estimates displayed significant heterogeneity (P<0.001).ConclusionsBreast MRI demonstrates an excellent diagnostic performance in case of non-calcified equivocal breast findings detected in conventional imaging. However, considering the substantial heterogeneity with regard to prevalence of malignancy, problem solving criteria need to be better defined.