Diagnosis of breast cancer: MDCT versus MRI.

In Japan, helical CT has been applied to breast cancers for the accurate determination of cancer extent before surgery. In recent years, multidetector CT (MDCT) has become commercially available. Compared with mammography and ultrasonography, MDCT of the breast is thought to be useful for preoperative assessment of breast-conserving surgery. In contrast, magnetic resonance imaging (MRI) is extremely accurate in the diagnosis of intraductal carcinoma and multicentricity of breast cancer. A real problem related to the use of CT is X-ray exposure. Therefore, it is controversial whether the use of CT for the patients with breast cancer is appropriate or not. Recent studies that compared the use of MDCT and MRI in the same patients concluded that MRI was more accurate for the detection and evaluation of the extent of intraductal carcinoma. We should consider the pitfalls and limitations of CT for assessing the breast cancer extent.