[Evaluation of enhancement patterns using three-dimensional dynamic contrast-enhanced MR imaging in 209 cases of breast cancer].

Abstract

Purpose: To evaluate contrast-enhanced patterns using three-dimensional (3D) dynamic MR imaging in 209 cases of breast cancer.

Materials and methods: Three-dimensional dynamic imaging of the breast (1.5-T scanner) was performed in 755 cases. Of 227 breast carcinomas, 209 cases that were histologically confirmed were enrolled in this study. The histological diagnoses included ductal carcinoma in situ (DCIS) (n=12), invasive ductal carcinoma (n=176), mucinous carcinoma (n=10), medullary carcinoma (n=4), invasive lobular carcinoma (n=6), and other (n=1). Tumor size was a mean 24.6 mm in diameter (range, 7-110 mm), including 110 cases of small breast carcinomas (< or = 2 cm). The contrast-enhancement pattern was analyzed from the early phase of 3D-MRI and the post-contrast T1-weighted SE image acquired before the delayed phase of 3D-MRI. The type of peripheral enhancement (PE) was evaluated on the early and delayed phases of 3D-MRI. These enhancement patterns were also compared with the histological findings of small breast carcinomas.

Results: The sensitivity of the 209 cases of breast carcinoma was 99% (207/209) on 3D dynamic MRI. Two hundred six cases (98.6%), including all DCIS, showed strong enhancement on the early phase of 3D MRI. An increased washout pattern showing signal intensity lower than that of fat on post-contrast T1-weighted imaging was noted in 201 cases (96.1%), of which 179 cases (85.6%) showed washout patterns. PE was identified in 63 cases (30.4%) and in 35 of 110 cases of small breast carcinoma (31.8%). Delayed PE following central washout was noted in 65% of 63 cases and 71.4% of 35 cases of small breast carcinoma. Delayed PE was well correlated with marginal fibrosis.

Conclusion: Three-dimensional dynamic MRI of the breast was highly sensitive for breast carcinoma. Delayed PE following central washout was considered a specific finding of breast carcinoma. It is important to understand the enhancement patterns of 3D dynamic MRI for excellent specificity of breast carcinomas.