DYNAMIC TURBOFLASH SUBTRACTION TECHNIQUE FOR CONTRAST-ENHANCED MR-IMAGING OF THE PROSTATE - CORRELATION WITH HISTOPATHOLOGIC RESULTS

PURPOSE: To assess whether a TurboFLASH (fast low-angle shot) magnetic resonance (MR) sequence can improve the accuracy of fast spin-echo (S E) endorectal coil MR imaging in the staging and localization of prost ate cancer. MATERIALS AND METHODS: In 57 patients with prostate cancer , MR imaging was performed with the following sequences: T1-weighted S E, T2-weighted fast SE, single-section gadolinium-enhanced dynamic sub tracted TurboFLASH (one image every 1.25 or 2.5 seconds), and late-pha se gadolinium-enhanced T1-weighted SE. Retrospectively, two blinded in dependent readers graded onset and steepest slope of enhancement and a ssessed tumor involvement and capsular penetration. MR findings were c orrelated with histopathologic results. RESULTS: On TurboFLASH images, prostate cancer was characterized by early and rapidly accelerating e nhancement compared with that of surrounding tissues. Average sensitiv ity, specificity, and accuracy for detection of tumor involvement for the two readers with TurboFLASH images were 73.5%, 81.0%, and 77.5%. T hese values with fast SE images were 57.5%, 80.5%, and 72.0%. Depictio n of capsular penetration and delineation and staging of tumor were be tter when TurboFLASH images were included with fast SE images. Differe nces between the two sequences, however, were not statistically signif icant. CONCLUSION: Because the TurboFLASH sequence did not statistical ly significantly improve tumor localization and staging results, routi ne use is not recommended. The technique may be useful for selected pa tients with equivocal evidence of capsular penetration.