Visualization of prostate cancer using dynamic contrast-enhanced MRI: comparison with transrectal power Doppler ultrasound.

This study was designed to assess the efficacy of dynamic contrast-enhanced MRI (DCE-MRI), in comparison with power Doppler ultrasound (PDUS), for visualizing prostate cancer. 111 men suspected of having prostate cancer underwent imaging before undergoing octant biopsy. Subsequently, 31 cancer-positive patients were enrolled in this study. DCE-MRI was obtained using a three-dimensional fast-field echo sequence, which assured wide coverage of the prostate gland. The transrectal PDUS were scored according to the degree of power Doppler flow signals. The time intensity curve types for the DCE-MRI and the PDUS scores were compared with the histopathologic results for each region. The time intensity curves were correlated significantly with PDUS scores (p<0.001). Using PDUS, the overall sensitivity, specificity and accuracy of cancer visualization in peripheral zones were 69%, 61% and 66%, respectively. Using DCE-MRI, the corresponding values were 87%, 74% and 82%. In the inner gland, using PDUS, the overall sensitivity, specificity and accuracy were 68%, 94% and 83%, respectively. Using DCE-MRI, the corresponding values were similar (68%, 86% and 78%). DCE-MRI was significantly more sensitive than transrectal PDUS in peripheral zones (p<0.05). In conclusion, both transrectal PDUS and DCE-MRI can be used to demonstrate hypervascularity in many prostate cancers. DCE-MRI was significantly more sensitive than PDUS for visualizing of prostate cancers without loss of specificity in the peripheral zone.