DIAGNOSIS OF URETHRAL DIVERTICULA IN WOMEN - VALUE OF MR-IMAGING

OBJECTIVE. The purpose of this study was to determine the role of MR i maging in the diagnosis of urethral diverticula in women.SUBJECTS AND METHODS. In 20 patients (mean age, 47 years), MR imaging was performed (1.5-T); unenhanced T1-weighted and T2-weighted images and contrast-e nhanced T1-weighted images were obtained. MR imaging findings were com pared with findings on urethrograms (including voiding cystourethrogra ms or double balloon catheter studies) in 16 patients, urethroscopic f indings in 18, and surgical findings in 13. MR images were assessed fo r the presence, size, number, and location (anterior or posterior to t he urethral lumen and relationship to the neck of the bladder) of dive rticula, visualization of ostia, and presence of any concomitant compl ications. Sixteen of 20 patients had urethral diverticula: uncomplicat ed (simple) urethral diverticula in 13 patients; a diverticulum with a stone in one; a diverticulum with chronic granulation in one; and a d iverticulum with adenocarcinoma in one. In the remaining four patients , the diagnoses included Gartner's duct cyst (one) and paraurethral cy st (one); urethras were deemed to be normal in two. RESULTS. In 13 pat ients who had surgery, MR images correctly showed the presence or abse nce of diverticula, whereas urethrography was correct in nine (69%) an d urethroscopy in 10 (77%). Compared with surgical findings (20 divert icula in 12 patients), MR images depicted 14 (70%) of 20 diverticula a nd urethrography and urethroscopy each depicted 11 (55%) of 20. The os tium of the diverticulum could not be identified on MR images. The use of MR contrast material did not contribute to lesion detection, but t he enhanced images were superior to unenhanced images in showing granu lation tissue and carcinoma, although they did not help in their diffe rentiation. CONCLUSION. MR imaging is accurate for showing urethral di verticula, but owing to its high cost, it should be considered only wh en urethroscopic or urethrographic findings are equivocal or when pati ents are unable to undergo these procedures and clinical findings stro ngly suggest a urethral diverticulum.