Extension of breast cancer: comparison of CT and MRI.

PURPOSE: To compare three-dimensional (3D) helical CT with 3D MRI in the evaluation of intraductal spread of breast cancer.

METHODS: Fifty patients with breast cancer were examined. Tumor size ranged from Tis to T2. The whole breast was scanned by both breath-holding helical CT and MRI with contrast media. Linear or segmental enhancement, and spotty enhancement around the main tumor were considered to indicate ductal carcinoma in situ (DCIS) or ductal spread. These findings were compared with thin section histopathologic data.

RESULTS: Seventeen of 35 patients had intraductal spread with invasive cancer and 15 patients had DCIS. The sensitivity, specificity, and accuracy of 3D CT in detecting intraductal spread or DCIS were 71.9%, 83.3%, and 76.0%, respectively, and those of 3D MRI were 87.5%, 61.1%, and 78.0%. Overestimations numbered three (6.0%) on CT and seven (14.0%) on MRI, and underestimations numbered nine (18.0%) on CT and four (8.0%) on MRI.

CONCLUSION: 3D helical CT can provide good information about the spread of breast cancer and could be an alternative to 3D MRI for preoperative examination of breast cancer.