Diffusion-weighted MRI of urinary bladder and prostate cancers

PURPOSE The purpose of this study was to evaluate the feasibility of diffusion-weighted imaging in the diagnosis of the urinary bladder and prostate carcinomas. The apparent diffusion coefficient (ADC) values of the malignant and normal tissues were correlated. MATERIALS AND METHODS A total of 23 patients with 14 urinary bladder carcinomas and 9 prostate carcinomas, and 50 healthy controls with normal ultrasonographic urinary bladder and prostate gland imaging findings were enrolled in the study. The ADC values were reported as the mean standard deviation. Student's t test was performed to compare the ADC values of the normal and pathological tissues. Diffusion-weighted imaging (DWI) was performed with b factors of 0, 500, and 1000 s/mm(2), and the ADC values of the normal tissues and lesions were calculated. RESULTS The mean ADC value of the urinary bladder wall of the control group and bladder carcinomas were (2.08 +/- 0.22 x 10(-3) mm(2)/s) and (0.94 +/- 0.18 x 10(-3) mm(2)/s), respectively. In addition, the ADC values of the normal peripheral (2.07 +/- 0.33 x 10(-3) mm(2)/s), transitional zones (1.46 +/- 0.23 x 10(-3) mm(2)/s) of the prostate, seminal vesicles (2.13 +/- 0.13 x 10(-3) mm(2)/s) and the prostate carcinomas (1.06 +/- 0.17 x 10(-3) mm(2)/s) were calculated. The comparison of mean ADC values of the peripheral-transitional zones of the prostate, normal bladder wall-bladder carcinomas, and peripheral zone prostate carcinomas were statistically significant (P < 0.01). CONCLUSION The present study demonstrated that ADC measurement has a potential ability to differentiate carcinomas from normal bladder wall and prostate gland.