Radiologic detection and prostatic carcinoma by double contrast retrograde urethrocystography.

A method of radiologic visualization of the male urethra especially for detecting prostatic carcinoma is reported. This method is called double contrast retrograde urethrocystography and is similar to that of Flocks in combining air cystography and retrograde urethrography but it differs in the manner of making the exposure. In our method the exposure is made with the patient in an exaggerated Trendelenburgs position to allow the contrast medium injected into the bladder to accumulate at the dome. Thus, in the urethrocystogram obtained by this method, the bladder neck and the prostatic urethra immediately adjacent to it are always clearly visualized unlike that obtained by conventional retrograde urethrography, evacuation cystourethrography and sometimes even the method of Flocks, in which these regions are prone to be covered and masked by the contrast medium injected and accumulated in the bladder. Therefore, with our method the radiological detection and differentiation of the malignant lesion involving these regions are more accurate and definite. From our clinical experiences the mode of compression and displacement caused by benign prostatic hypertrophy is continuous and regular, while that caused by prostatic carcinoma is interrupted, irregular and with moth-eaten and granular defects. Four cases are reported.