Three-dimensional ultrasound imaging system for prostate cancer diagnosis and treatment

Prostate cancer is the most commonly diagnosed cancer in men in North Ameri ca. Although two-dimensional (2-D) transrectal ultrasound imaging is widely used for the evaluation of prostate disease, it suffers from limitations t hat limit its use in diagnosis and therapy of prostate cancer. The use of c onventional ultrasound requires that the diagnosticians mentally integrate a series of 2-D images in order to develop an impression of the three-dimen sional (3-D) anatomy, and to estimate the volume of the prostate. This appr oach depends of the expertise of the physician resulting in variability. We have developed a 3-D ultrasound imaging approach that overcomes this probl em. in this paper, we describe a 3-D ultrasound imaging system for use in p rostate imaging and report on its performance. The system consists of a con ventional ultrasound machine, a microcomputer with an video frame grabber, and a custom-built assembly for rotating the ultrasound transducer. A typic al scan of 100 2-D B-mode images takes 8 s, These images are then reconstru cted into a 3-D image, which can be displayed and interactively manipulated using 3-D visualization software. We also show that manual planimetry of p rostates in the 3-D images can be used to estimate volumes in vitro with an accuracy of 2.6%, and a precision of 2.5%; and in vivo with 5.1% intra-obs erver variability and 11.4% interobserver variability. Thus, 3-D ultrasound imaging overcomes some of the limitations of conventional imaging of the p rostate, and has great potential as a tool in the diagnosis and treatment o f prostate disease.