Magnetic resonance imaging of the pelvis: prostate and urinary bladder.

Magnetic resonance imaging has opened up a new horizon in the evaluation of the male pelvis. Its direct multiplanar imaging and display of the unique tissue contrast allows for the demonstration of prostate anatomy. Prostatic disease, even when confined to the gland, is easily depicted. However, one cannot distinguish benign from malignant processes. In a patient with a known prostatic neoplasm, magnetic resonance is useful as a staging modality. Accuracy in the staging of prostatic malignancies by MRI surpasses that of ultrasound or CT. In the evaluation of the urinary bladder, the greatest advantage of magnetic resonance is its ability to differentiate between a normal bladder, and other pathologic conditions affecting the bladder, including inflammatory, congestive and neoplastic processes. In the evaluation of bladder carcinoma, magnetic resonance is useful as a staging modality. Clinical application of magnetic resonance is just beginning and therefore, the full potential of the modality has yet to be explored.