Magnetic resonance imaging urodynamics. Technique development and preliminary results

Can Stress Urinary Incontinence Be Predicted by Ultrasound?

OBJECTIVE. The purpose of this study is to determine the value of translabial real-time 3D ultrasound for predicting stress urinary incontinence (SUI). SUBJECTS AND METHODS. From December 2012 to August 2016, women with or without SUI diagnosed by urologists via urodynamics were prospectively recruited. All subjects underwent translabial real-time 3D ultrasound at one institution. Volume data were analyzed offline by a radiologist who was blinded to the diagnosis and who evaluated the bladder neck position on maximal Valsalva maneuver, the levator hiatus area on maximum Valsalva maneuver, bladder neck descent, and the urethral rotation angle. Combinations of two, three, and four parameters were analyzed using Fisher linear discriminant analysis. ROC curves were constructed to determine the optimal cutoff values of the four parameters and all combinations of parameters to predict SUI. RESULTS. A total of 321 women with SUI (mean [± SD] age, 35 ± 11 years) and 90 women without SUI (mean age, 31 ± 8 years) were included. Only 337 women were included in the final study, to eliminate the confounder of age. The cutoff values for the bladder neck position on maximal Valsalva maneuver, the levator hiatus area on maximum Valsalva maneuver, bladder neck descent, and the urethral rotation angle as parameters predicting SUI were 1 mm, 19 cm², 24 mm, and 45°, respectively. For all combinations of parameters, the negative predictive values were more than 90%, although none of the combinations had a sensitivity higher than 70%. The specificities were approximately 95% when three or four parameters were included. The positive predictive value of the combinations ranged from 49.2% to 84.8%. CONCLUSION. Translabial real-time 3D ultrasound is insufficient for predicting SUI, but it can be used to identify women without the condition.

Protocol for a prospective observational study of cortical lower urinary tract control changes following intradetrusor injection of botulinum toxin-A in patients with multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a severe debilitating disease that affects patients' quality of life. Up to 90% of patients with MS will develop lower urinary tract dysfunction within the first 18 years of the disease. If oral pharmacotherapy with anticholinergics, behavioural modifications and pelvic floor physical therapy are unsuccessful, intradetrusor injection of botulinum toxin-A (OnaBotA; Botox Allergan, Dublin, Ireland) is a highly effective option for these patients. The local effects of OnaBotA are well understood, but not much is known of its afferent/sensory effects while treating the end organ. Our study will use functional MRI (fMRI) and task-related blood oxygen level-dependent signals to evaluate patients with MS and neurogenic detrusor overactivity (NDO) prior to, and after, intradetrusor injection of OnaBotA with simultaneous urodynamic evaluation. Urinary concentration of brain-derived neurotrophic factor and nerve growth factor will also be collected since it has been shown that patients with an overactive bladder have higher concentrations of these neuropeptides.

METHODS AND ANALYSIS

Female patients with MS and lower urinary tract symptoms who previously have undergone urodynamic screening and are refractory to conservative and oral pharmacotherapy management for NDO and are interested in OnaBotA intradetrusor injection will be invited to participate in the study. An fMRI will be performed preintradetrusor injection and postintradetrusor injection of OnaBotA with simultaneous MRI compatible with material urodynamics. Images will be collected and analysed accordingly.

ETHICS AND DISSEMINATION

All of the patients are properly consented before enrolling in this study that has been previously approved by the Institutional Review Board. Results of neural connectivity activation will be presented at national and international meetings and published in scholarly journals.

Magnetic resonance imaging in assessment of stress urinary incontinence in women: Parameters differentiating urethral hypermobility and intrinsic sphincter deficiency

AIM: To define the magnetic resonance imaging (MRI) parameters differentiating urethral hypermobility (UH) and intrinsic sphincter deficiency (ISD) in women with stress urinary incontinence (SUI).

METHODS: The static and dynamic MR images of 21 patients with SUI were correlated to urodynamic (UD) findings and compared to those of 10 continent controls. For the assessment of the urethra and integrity of the urethral support structures, we applied the high-resolution endocavitary MRI, such as intraurethral MRI, endovaginal or endorectal MRI. For the functional imaging of the urethral support, we performed dynamic MRI with the pelvic phased array coil. We assessed the following MRI parameters in both the patient and the volunteer groups: (1) urethral angle; (2) bladder neck descent; (3) status of the periurethral ligaments, (4) vaginal shape; (5) urethral sphincter integrity, length and muscle thickness at mid urethra; (6) bladder neck funneling; (7) status of the puborectalis muscle; (8) pubo-vaginal distance. UDs parameters were assessed in the patient study group as follows: (1) urethral mobility angle on Q-tip test; (2) Valsalva leak point pressure (VLPP) measured at 250 cc bladder volume; and (3) maximum urethral closure pressure (MUCP). The UH type of SUI was defined with the Q-tip test angle over 30 degrees, and VLPP pressure over 60 cm H₂O. The ISD incontinence was defined with MUCP pressure below 20 cm H₂O, and VLPP pressure less or equal to 60 cm H₂O. We considered the associations between the MRI and clinical data and UDs using a variety of statistical tools to include linear regression, multivariate logistic regression and receiver operating characteristic (ROC) analysis. All statistical analyses were performed using STATA version 9.0 (StataCorp LP, College Station, TX).

RESULTS: In the incontinent group, 52% have history of vaginal delivery trauma as compared to none in control group (P < 0.001). There was no difference between the continent volunteers and incontinent patients in body habitus as assessed by the body mass index. Pubovaginal distance and periurethral ligament disruption are significantly associated with incontinence; periurethral ligament symmetricity reduces the odds of incontinence by 87%. Bladder neck funneling and length of the suprapubic urethral sphincter are significantly associated with the type of incontinence on UDs; funneling reduced the odds of pure UH by almost 95%; increasing suprapubic urethral sphincter length at rest is highly associated with UH. Both MRI variables result in a predictive model for UDs diagnosis (area under the ROC = 0.944).

CONCLUSION: MRI may play an important role in assessing the contribution of hypermobility and sphincteric dysfunction to the SUI in women when considering treatment options.