Figure 14d. Causes and radiologic features of acquired urethrorectal fistulas in four patients. (a) Contrast-enhanced CT image shows a fistula (arrow), which was due to cryoablation of a prostatic carcinoma. Air pockets that extend to the urethra (arrowhead) are seen in the prostate. (b) Retrograde urethrogram shows leakage of contrast material into the rectum (R). The fistula was the result of radiation seed therapy in the prostate (arrowhead). (c) VCUG image of a patient with a prostatic abscess shows leakage of contrast material at the prostatic urethra (arrowheads) with opacification of the rectum (R). (d) VCUG image shows a fistula (arrow), which was a complication of transperineal prostatectomy.