Evaluation of stress urinary incontinence by computer-aided vector-based perineal ultrasound.

BACKGROUND In this study, we compared the differences in dynamic changes of the bladder neck between women with and without urodynamic stress incontinence by computer-aided vector-based perineal ultrasound. METHODS The function and morphology of the lower urinary tract were assessed in 48 women with or without urodynamic stress incontinence by urodynamic study and computer-aided vector-based perineal ultrasound. RESULTS Patients in the urodynamic stress incontinence group had a significantly higher parity and higher prevalence of funneling of the bladder neck than participants in the control group (p<0.05). After adjusting for parity, women with a corrected bladder neck movement > or =10 mm were 9.0 times more at risk of having urodynamic stress incontinence than women with a corrected bladder neck movement <10 mm (p < 0.05). If we used corrected bladder neck movement > or =10 mm as the cut-off point for diagnosis of urodynamic stress incontinence, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 77.8%, 66.7%, 87.5%, 50%, and 75%, respectively. CONCLUSIONS The increase in corrected bladder neck movement is associated with functional impairment of urethral closure. Computer-aided vector-based perineal ultrasound is valuable in assessing anatomic change of the bladder neck, but it is not a sensitive tool for predicting urodynamic stress incontinence.