A systematic comparison of abbreviated and unenhanced breast MRI protocols in women with mammographically dense breasts compared to full multiparametric breast MR imaging.

[OBJECTIVE] While the feasibility of MRI as a supplemental screening tool for breast cancer has been established, there is no consensus regarding the optimal examination protocol. This reader study aims to provide a systematic comparison of abbreviated contrast-enhanced MRI, IV-contrast-free, and a full multiparametric protocol, to diagnose breast cancer in a population of women with mammographically dense breasts.

[MATERIALS AND METHODS] This IRB-approved retrospective reader study was performed in 166 patients with mammographically dense breasts recruited from a tertiary care university hospital. MR images were acquired at 1.5 or 3 T MRI units in line with international recommendations. Three blinded off-site readers evaluated the images in three different approaches in a region-wise analysis: (1) full multiparametric protocol, (2) abbreviated first pass MRI protocol, and (3) unenhanced DWI and T2w/STIR images. Histopathology and/or imaging follow-up of at least 24 months served as a reference standard. Statistics included generalized estimating equation methodology based logistic regression for repeated measures.

[RESULTS] 1660 regions (166 women, mean age, 45 +/- 12 years) with 41 histologically verified cancers were read. At a BI-RADS cutoff > 3, sensitivity was significantly higher (p < 0.001) using the full protocol (80.4-90.2%) followed by the abbreviated (70.7-78.1%) and lastly the unenhanced protocol (40.6-53.5%). Specificity was significantly lower (p < 0.001) using the abbreviated protocol. Inter-reader agreement was fair to moderate.

[CONCLUSION] The full multiparametric protocol demonstrated superior sensitivity compared to the abbreviated and unenhanced protocol, while specificity of the full and unenhanced protocols were superior to the abbreviated protocol.