MR imaging of patients undergoing prostatic balloon dilation

Nine patients who had prostatic balloon dilation for benign prostatic hyperplasia were examined with MR imaging. Seven patients had increased periurethral prostatic T2 signal that cleared within weeks of dilation. In five of six patients who had predilation MR imaging, the prostate enlarged with dilation but returned to the predilation size or smaller within weeks. Disruption of the prostate capsule or surrounding tissues was not observed. These findings suggest that balloon dilation causes prostatic hemorrhage or edema followed by shrinkage, possibly the result of fibrosis