STAGING PROSTATE-CANCER WITH MR-IMAGING - A COMBINED RADIOLOGIST-COMPUTER SYSTEM

PURPOSE: To test the accuracy of a combined radiologist-computer syste m in the diagnosis with magnetic resonance (MR) imaging of cancer of t he prostate gland. MATERIALS AND METHODS: The combined system was deve loped and tested by four specialists in prostate MR imaging and five r adiologists expert in body MR imaging. Each group read MR images obtai ned in 100 proved cases of prostate cancer. The images were obtained f rom two sources, and all were obtained with an endorectal surface coil . Prostate MR specialists ranked imaging features of cases to develop a checklist for image interpretation. Features with greatest diagnosti c value were incorporated in the combined system. Accuracy measures we re derived from the area index of the receiver operating characteristi c curve for the combined system and compared with those of radiologist s working alone. RESULTS: Body MR radiologists had a mean baseline acc uracy of 0.67; mean accuracy of their combined system was 0.80. The pr ostate MR specialists, when they rated the features in each case, had a mean accuracy of 0.81; the accuracy of their combined system was 0.8 7. CONCLUSION: A combined radiologist-computer system substantially im proved accuracy of body MR radiologists in the diagnosis of prostate c ancer. High levels of accuracy were also achieved by the system with p rostate MR specialists.