RESUMO
Authors report about the role of contrast medium enhanced magnetic resonance imaging in diagnosis of breast diseases, and experiences with this method. The aim of the study was to determine the diagnostic accuracy of the method. The results was correlated with the histopathological findings, and compared to the diagnostic accuracy of the conventional X-ray mammography in breast lesions. X-ray and MR-mammography were evaluated in 220 patients (238 breasts) scheduled for breast surgery. The breasts were examined with T1-weighted transversal images using contrast medium enhanced semidynamic technique with 3D fast low angle shot (FLASH) sequence. Each breast was given a routine examination with 3 mammographic views. Contrast enhanced MR-mammography is a highly sensitive method for the detection of breast cancer, it has a higher diagnostic accuracy (84.5%), than conventional X-ray mammography (82.4%). When MRI and conventional X-ray mammography were used together, very high sensitivity but a lower diagnostic accuracy (81.5%) was achieved. MRI was effective in revealing mammographically equivocal or occult lesions and multifocal tumors even in dense breasts, but it was less reliable for some invasive lobular cancers, non-invasive ductal carcinomas, fibroadenomas and hyperplastic breast changes. Presently accepted indications for MRI of the breast are: (1) patients with breast implants--to demonstrate prothesis complications and tumor relapses; (2) postoperative imaging in patients after tumorectomy and radiation therapy--in these cases MRI allows differentiation between tumor relapses and extensive scars; (3) proven axillary lymph node metastasis from an unknown primary carcinoma; (4) preoperative MR imaging in cases suspected or verified carcinomas within dense breasts to exclude multicentricity/multifocality; (5) follow-up in chemotherapy of breast cancer; (6) patients with high-risk constellation.
