Magnetic resonance mammography of breast cancer. Assessment of MR imaging pulse sequence

This investigation was performed to assess the usefulness of magnetic resonance imaging in the diagnosis of breast cancer. MR images were obtained of the breasts of 74 patients with 86 masses pathologically diagnosed as carcinoma. MR mammography (MRM) was performed with a 1.0 Tesla magnet, and the patients were placed in the prone position with the breast hanging downwards using a breast-specific coil. Coronal, axial and oblique images were selected. T1-weighted images, T2-weighted images, proton density-weighted images and short TI IR method images were obtained. After these images were obtained, gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) was injected in a bolus at a dose of 0.2 mmol/kg of body weight. The profile study was performed with a short TR/TE spin-echo sequence or a field-echo sequence. Single sections were obtained before, during, and up to six minutes after i.v. injection of Gd-DTPA. Delayed T1-weighted enhanced images were also obtained. After the breasts were removed, same sequence images were performed for the 21 specimens, which were wrapped up in plastic bags, as soon as possible. The subtraction images were also computed. STIR and subtraction were the most useful method to detect breast masses on plain MR imaging, and oblique sagittal images were valuable to detect swollen axillary lymph nodes. Breast carcinomas and fibroadenomas showed characteristic time-intensity curves on dynamic field-echo sequence MR imaging. A potential role for MR imaging is in the preoperative staging of cancer to decide on the surgical approach, and it should be used to improve the sensitivity for detecting masses that cannot be visualised by conventional mammography and ultrasound. (author)