Magnetic resonance (MR) imaging, when used in conjunction with mammography and ultrasonography, can be a powerful tool for breast imaging. There are various clinical scenarios in which MR imaging may provide key information that leads to an alteration in treatment plans (eg, by demonstrating features that were occult at physical examination or conventional imaging). Although many benign and malignant entities enhance at contrast material-enhanced breast MR imaging, the morphologic characteristics and kinetic profiles of lesions help narrow the differential diagnosis. To optimize the quality of the morphologic and kinetic information yielded by breast MR imaging, the radiologist must attend to various practical and technical prerequisites: A bilateral breast coil should be used with prone positioning of the patient. An MR imaging system with a high-field-strength magnet is needed, and the magnetic field must be homogeneous across the field of view, which should include both breasts. A T2-weighted sequence should be applied first to identify any cysts and should be followed by three-dimensional imaging with a T1-weighted spoiled gradient-echo sequence after the intravenous administration of a gadolinium chelate. To minimize artifacts, a direction other than the anterior-posterior direction should be selected for phase encoding. To suppress the signal from fat, a frequency-selective pulse should be applied during imaging, or the unenhanced MR imaging data should be subtracted from the contrast-enhanced MR imaging data during postprocessing. The imaging section thickness should be 3 mm or less, the pixel size should be less than 1 mm in each in-plane direction, and the total acquisition time should be less than 2 minutes.
Copyright RSNA, 2006.