Magnetic resonance imaging in the evaluation of urologic malignancies.

Although MRI has been available for clinical use for only a short time it has already proven its value in the diagnosis and staging of renal malignancies and has shown promise in evaluation of malignancies of the lower urinary tract. Its excellent tissue contrast discrimination, ease of evaluation of vascular structures and perivascular lymph nodes and its capability for multiplanar imaging contribute to this promise. Its dependence on multiple tissue and imaging parameters allows manipulation of images to permit evaluation of a variety of structures for anatomic and physiologic abnormalities. Its lack of ionizing radiation and the absence of requirement for intravenous contrast agents are attractive features in evaluation of genitourinary structures. Clinical experience with MRI in diagnosis and staging of urologic malignancies is growing in a number of academic centers, and MRI units are being installed in many private hospitals. It is anticipated that the importance of MRI in the evaluation of the genitourinary tract will increase rapidly as this technology becomes widely available.