MRI characteristics of ductal carcinoma in situ of the breast

Objective To evaluate and recognize the dynamic and morphological MRI charactristics of ductal carcinoma in situ (DCIS) of the breast and provide imaging information for the early detection and treatment planning Methods All MRI data in 71 patients with histollogically proved DCIS were analyzed retrospectively. The 71 patients were divided into two groups, NI ( pure DCIS, 44 patients) and N2 ( DCIS with microinvasion, 27 patients). According to the BI-RADS descriptors, all lesions were defined as a focus (smaller than 5 mm in diameter), mass and no-mass-like three enhancement types. The morphological features (M1 = focus, M2 = linear or linear-branched, M3 = branching-ductal, M4 = segmental, M5 = focal,M6 = regional, M7 = diffuse, M8 = mass) and the time-intensity curve (TIC) pattern [type l ( persistent enhancement curves), type Ⅱ( plateau), type Ⅲ(washout) and type Ⅳ (the same enhancement as glandular tissue)] were described. Chi-square test was used for the morphological characteristics of lesions.Results The 73 DCIS lesions were found in 71 patients, and 5.5% (n =4) were stippled lesions, 87.7%( n =64) were no-mass-like lesions, 6.8%(n=5) were mass-like lesions. In no-mass-like lesions (n=64), M3 was found in 15 cases, M4 in 34 cases, M5 in 9 cases and M6 in 6 cases, respectively, M3 and M4 were the most common distribution patterns. In N1 group(n =45) and N2 group (n =28), M3, M4,M5, M6 were found in 7 and 8, 21 and 13, 7 and 2, 3 and 3 cases, respectively. There were no statistic differences between two groups (P＞0.05). In 31 showed heterogeneous enhancement, both M3 and M4 were observed in 35.5% (11/31). In 26 clustered ring enhancement lesions, M4 was observed in 88.5% (23/26). Four lesions showed reticular enhancement,2 lesions showed a clumped enhancement and 1 lesion showed homogeneous enhancement. In 5 mass-like lesions, N1 group had 3 cases, N2 group had 2 cases.Four lesions showed lobulated margin, 4 lesions showed speculated margin, 1 mass showed smooth margin.Five mass showed heterogeneous enhancement. Type Ⅰ , type Ⅱ , type Ⅲ and type Ⅳ TIC ( n = 25) were demonstrated in 8, 11, 3 and 3 lesions, respectively. Conclusions M3, M4, especially segmental clustered ring enhancement, are the most common morphological characteristics of DCIS. Type Ⅰ and type Ⅱ TIC are the most common types. Key words: Carcinoma,ductal,breast;  Magnetic resonance imaging;  Image enhancement