To evaluate the contrast-enhanced MR findings of lesions associated with a radial scar and to compare the MR findings with the histopathology results.

From Mar. 2001 to Sep. 2005, 8 patients with a surgically proven radial scar who had undergone MRI, mammography, and ultrasonography were enrolled in this study. The morphological findings and dynamic enhancement pattern of the time-intensity curve were retrospectively reviewed using non-contrast and contrast-enhanced MRI. Mammography and ultrasonography were also analyzed according to the BI-RADS category and correlated with the histopathological diagnosis.

The age of the patients ranged from 42 to 53 years (mean, 47 years). Five patients presented with a left breast lesion and the others presented with a right breast lesion. The histopathological diagnosis associated with the radial scar were fibrocystic changes (n=1), adenosis (n=2), atypical ductal hyperplasia (n=2), lobular carcinoma in situ (n=1), ductal carcinoma in situ (n=1), and invasive ductal carcinoma (n=1). In all patients, architectural distortion without microcalcification was observed with mammography. Irregular shaped hypoechoic lesions with an indistinct, spiculated, or angular margin was observed in all patients with ultrasonography. Posterior shadowing was observed in 4cases. MR enhancement revealed two cases with foci enhancement (adenosis and fibrocystic change), five cases with non-mass-like focal enhancement (fibrocystic change, atypical ductal hyperplasia, lobular carcinoma in situ, ductal carcinoma in situ, invasive ductal carcinoma), and one irregular homogeneous mass enhancement (atypical ducal hyperplasia). The time-signal intensity curves are as follows: persistent type (n=2), adenosis, and fibrocystic changes, respectively; plateu type (n=4), one adenosis, two atypical ductal hyperplasia, and one ductal carcinoma in situ; and washout type (n=2), lobular carcinoma in situ, and invasive ductal carcinoma, respectively.

Although a combined benign or malignant pathology with a radial scar was not predicted on the preexisting image modality, contrast-enhanced MRI can help to predict a combined benign or malignant pathology with a radial scar using the morphological findings and the dynamic enhancement type of the time-intensity curve.