Abstract: Objective  To evaluate the potential of breast MRI in predicting the presence of invasion by comparing the morphologic and kinetic characteristics between pure ductal carcinoma in situ (DCIS) and DCIS with early invasion. Methods  Preoperative breast MRI of 82 pure DCIS lesions(N1 group)and 51 DCIS lesions with early invasion (N2 group) were reviewed retrospectively. The morphologic characteristics and time-intensity curve (TIC) of all lesions were described in accordance with American College of Radiology Breast Imaging Repot and Data System (ACR BI-RADS). All cases were confirmed by surgery and pathology. Statistical analyses were performed through univariate and multivariate logistic regression approach. Results  Lesion size and delayed TIC were associated with the presence of early invasion. Compared with lesion size ＜1.9cm, the probability of invasion was higher for lesion size ≥1.9cm (OR=2.285, 95% CI:1.110-4.663). Compared with persistent TIC, the probability of invasion of washout TIC was 4.773 times (95%CI:1.880-12.118)and the probability of plateau TIC was 2.657 times (95%CI:1.089-6.482). The majority of both pure DCIS and DCIS with early invasion were depicted as non-mass-like enhancement, and there was no significant difference in morphology between two types of lesions(P＞0.05). Conclusion  Lesion size and delayed TIC on breast MRI have the potential in predicting the presence of early invasion in DCIS.

Key words: Breast, Decision analysis, Ductal carcinoma in situ, MRI