MRI evaluation of urethral diverticula and differential diagnosis in symptomatic women
OBJECTIVE. The purpose of this study was to evaluate the role of MRI in the diagnosis and differential diagnosis of urethral diverticula in symptomatic women. MATERIALS AND METHODS. Women referred for MRI at a single institution because of suspicion of urethral diverticula were included. All MRI examinations were independently evaluated by two radiologists and compared with patients' follow-up data. Sensitivity and specificity of MRI for urethral diverticula were calculated using surgery and clinical confirmation as the reference standards. Image quality of the urethra and periurethral region performed with the endoluminal coil was compared with the pelvic phased-array coil. RESULTS. From a study group of 60 patients (mean age, 44 years), 20 patients (33%) had urethral diverticula and 28 (47%) had an alternative diagnosis, of which 13 (46%) were visualized with MRI. In the remaining 12 patients (20%) no abnormalities were found. For urethral diverticula, MRI had both sensitivity and specificity of 100%. Twenty patients had a total of 27 diverticula; these were mostly locally round (n = 12) with sharp margins (n = 25) and high (n = 19) homogeneous (n = 16) signal intensity on T2- weighted sequences. The ostium of urethral diverticula was identified in 23 diverticula (85%) by both readers. Agreement was 93% with κ = 0.72. Endoluminal coil placement in the vagina showed the best image quality of the urethra and periurethral region. CONCLUSION. Dedicated MRI is an excellent imaging modality for urethral diverticula; furthermore, MRI will show the alternative diagnosis in almost one half of the remaining patients.