Transrectal ultrasonic volume determination of the prostate--a preoperative and postoperative study.

A technique for transrectal ultrasonic volume determination of the prostate, based on the principle of serial planimetry, is presented. The preoperative ultrasonic determinations in 75 cases have been compared to the estimation of size by digital palpation and to the amount of tissue removed at operation. Scannings 6 to 10 weeks postoperatively have shown variable amounts of residual prostatic tissue. The difference in the preoperative and postoperative ultrasonic volume has been compared to the amount of tissue resected at operation, and the accuracy of the method has been established. The transrectal approach gives a close and complete view of the prostate, and has proved to be a simple, easily applicable and reliable method for volume determination. Postoperative scannings show morphological changes in the resection cavity, which are difficult to explain from scanning alone.