前立腺癌の鑑別診断としての逆行性尿道膀胱二重造影法(D-RUC)の意義

Abstract

A new method for radiologic visualization of the prostatic urethra, bladder neck, bladder neck lumen and bladder neck floor is reported. It is a combination of air cystogram and retrograde urethrogram with the patient in an exaggerated Trendelenburg's position allowing the contrast medium injected into the bladder to be accumulated at the bladder base and dome far from trigone. This method is called double constrast retrograde retrograde urethrocystography (D-RUG). In the urethrocystograms made by this method the bladder neck and the prostatic urethra immediately adjacent to it are always clearly visualized, unlike in those obtained by conventional retrograde urethrocystography, evacuation cystourethrography and even by the method Flocks, in which these regions are prone to be covered and masked by the contrast medium injected and accumulated in the bladder. From 1975 to 1980, a total of 750 patients with prostatism seen at our outpatient clinic were radiologically examined with this new method. Of dIem, 533 patients (419 benign prostatic hyperplasia, 42 prostatic carcinoma, 15 prostatic carcinoma suspected, 57 prostatitis complicated prostatic hyperplasia) were admitted and operated. Clinical and retrospective studies on the double contrast retrograde urethrocystograms obtained from these operative cases were made to correlate the modes of compression and displacement upon the prostatic urethra, bladder neck, bladder neck lumen and bladder neck floor caused by benign prostatic hyperplasia and by prostatic carcinoma. The conclusion is that the modes of compression and displacement caused by benign prostatic hyperplasia are continuous, thin and spread out regularly and evenly without interruption or any uneven defect, while those caused by prostatic carcinoma are interrupted, irregular, with moth-eaten and uneven granular defects. Substantially this new method is by far superior to other conventional urethrocystographies for the detection of prostatic carcinoma.