[Imaging of prostatic cancer by 1.5 Tesla nuclear resonance tomography].

Twenty-two patients with histologically confirmed carcinomas of the prostate were examined by nuclear magnetic resonance, using a 1.5 Tesla magnet (stage T1: one patient, T2: eight patients, T3: six patients, T4: seven patients). In 19 out of the 21 patients in stages T2 to T4, the tumour showed a specific signal intensity. In 12 cases, the tumour signal was more intense than from a normal prostate when using medium repetition and echo delay times; in 19 cases, multi-echo sequences with increasing echo delay time (30 to 240 ms) and long repetition times (usually 1600 ms) showed less reduction in signal intensity than surrounding structures (except urine). Unlike computed tomography, 1.5 Tesla MR is able to demonstrate carcinomas confined to the prostate. Demonstration of infiltration is possible with MR with great accuracy because of the ability to obtain images in three planes and because of the accurate rendering of soft tissue detail. In particular, MR differentiates between stages T2 and T3 more clearly than does CT. The best demonstration of anatomical structures in the true pelvis is achieved with a repetition time of 800 ms and an echo delay time of 30 ms, the best demonstration of tumour with corresponding 1600 ms and 120 ms. The effect of catheters in the bladder, or previous transurethral resection on the MR images is discussed.