Enhanced Masses on Contrast‐Enhanced Breast: Differentiation Using a Combination of Dynamic Contrast‐Enhanced MRI and Quantitative Evaluation with Synthetic MRI

Background The addition of synthetic MRI might improve the diagnostic performance of dynamic contrast‐enhanced MRI (DCE‐MRI) in patients with breast cancer. Purpose To evaluate the diagnostic value of a combination of DCE‐MRI and quantitative evaluation using synthetic MRI for differentiation between benign and malignant breast masses. Study Type Retrospective, observational. Population In all, 121 patients with 131 breast masses who underwent DCE‐MRI with additional synthetic MRI were enrolled. Field Strength/Sequence 3. 0 Tesla , T 1 ‐weighted DCE‐MRI and synthetic MRI acquired by a multiple‐dynamic, multiple‐echo sequence. Assessment All lesions were differentiated as benign or malignant using the following three diagnostic methods: DCE‐MRI type based on the Breast Imaging–Reporting and Data System; synthetic MRI type using quantitative evaluation values calculated by synthetic MRI; and a combination of the DCE‐MRI + Synthetic MRI types. The diagnostic performance of the three methods were compared. Statistical Tests Univariate (Mann–Whitney U ‐test) and multivariate (binomial logistic regression) analyses were performed, followed by receiver‐operating characteristic curve (AUC) analysis. Results Univariate and multivariate analyses showed that the mean T 1 relaxation time in a breast mass obtained by synthetic MRI prior to injection of contrast agent (pre‐T 1 ) was the only significant quantitative value acquired by synthetic MRI that could independently differentiate between malignant and benign breast masses. The AUC for all enrolled breast masses assessed by DCE‐MRI + Synthetic MRI type (0.83) was significantly greater than that for the DCE‐MRI type (0.70, P < 0.05) or synthetic MRI type (0.73, P < 0.05). The AUC for category 4 masses assessed by the DCE‐MRI + Synthetic MRI type was significantly greater than that for those assessed by the DCE‐MRI type (0.74 vs. 0.50, P < 0.05). Data Conclusion A combination of synthetic MRI and DCE‐MRI improves the accuracy of diagnosis of benign and malignant breast masses, especially category 4 masses. Level of Evidence 4 Technical Efficacy Stage 2 J. MAGN. RESON. IMAGING 2021;53:381–391.