Assessment of magnetic resonance imaging of the breast using 0.5 T equipment

To evaluate the efficacy of a magnetic resonance imaging technique of the breast using half-field equipment (0.5 T). We evaluated 191 magnetic resonance (MRI) studies made at our center from March 1998 to March 2001 using Signa Contour 0.5 T MRI equipment of General Electric. A dedicated bilateral breast made at fat saturation in the coronal plane before administering intravenous gadolinium, then 6 consecutive times after contrast administration. The sequence acquisition time was 70-90 seconds Image post processing included subtraction and analysis of the intensity/time curves in the region of interest (ROI) together with morphological evaluation of the lesion. Additional T2 weighted fast-spin-echo sequences (FSE T2), T1-weighted spin-echo (SE T1), FSE T2 with fat suppression, and STIR with water saturation were made for studies of breast implants. The clinical indications for MRI study of the breast were masses (n=79), microcalcifications (n=7), asymmetry (n=17), cases of indeterminate risk (n=7), postoperative control (n=51), and breast implants (n=25). The histological diagnosis was benign in 31 lesions and malignant in 73 lesions. The sensitivity specificity, and reliability of breast MRI were 93%, 81% and 89% respectively. Multicenter/multifocal neoplasms were found in 8% of patients and bilateral neoplasms in 2%. The therapeutic attitude was modified in 18% of the patients with breast cancer as a result of MRI findings. The results confirm the usefulness of MRI in the management of patients with breast cancer. Likewise, the present study demonstrated that breast MRI can be carried out with half-field equipment with the same reliability as with full-field equipment as long as specific breast cots are used rapid 3D sequences, and image processing with suitable software. (Author) 28 refs