Clinical Applications Of Pelvic Floor Dynamic MRI In Female Stress Urinary Incontinence

Objective:To assess urethral anatomy and function abnormalities of patients with female stressurinary incontinence (SUI) using pelvic floor dynamic MRI (Dynamic Magnetic ResonanceImaging, dMRI), meanwhile assess comprehensively the condition of pelvic organ prolapse(POP) combined, and to research the clinical applications of Pelvic Floor Dynamic MRI inFemale SUI.Methods:1. A retrospective analysis was performed on60cases of female stress urinaryincontinence treated in urology of our hospital from February2011to November2013. Thebasic clinical information about the patient was collected.2. Physical examination of patients with stress urinary incontinence: stress-inducedtest, bladder neck lifting test, Q-Tip test; According to POP-Q standard of theInternational Continence Society, the pelvic organ prolapse was diagnosed and graded.3. The pelvic floor dynamic MRI examination and image analysis were carried out,and the median sagittal plane of stress-phase dynamic MRI was measured by image lining:the urethral angle, the length of H line, the length of M line, the distance of bladder neckacross PCL, the distance of cervix across PCL, the distance of anorectal junction across PCL,and depth of wall protrusion beyond the expected margin of the normal anorectal wall.4. The urodynamic parameters was examined and recorded: functional urethral length,maximum urethral closure pressure, Valsalva leak-point pressure (VLPP), residual urine,maximum urine flow rate, average urine flow rate, urination resistance, detrusor pressure atmaximum flow rate, Detrusor opening pressure.5. The correlation between parameters of dynamic MRI and parameters of urodynamicwas performed by Pearson’s correlation analysis; the consistency analysis of POP-Q anddynamic MRI diagnosis of pelvic organ prolapse was performed by Kappa test. Results:1．Physical examination:51cases (85%) of anterior vaginal prolapse were diagnosedby POP-Q physical examination, of which31cases were of grade Ⅰ,10cases of grade Ⅰ,6cases of grade Ⅲ, and4cases of grade Ⅲ;8cases (13.34%) were of uterine prolapse, ofwhich4cases were of gradeⅠ,3cases of grade Ⅰ,1cases of grade Ⅲ, and2cases ofgrade Ⅲ;7cases (11.67%) were of vaginal wall prolapse, of which4cases were of gradeⅠ,1cases of grade Ⅰ,0cases of grade Ⅲ, and2cases of grade Ⅲ.2. Dynamic MRI of the pelvic floor examination and image analysis: in60patients(100%), the urethral angle was>30°and urethral funnelling were observed under stressphase, and in23patients (38.33%), urethral funnelling were observed under resting phase.Dynamic MRI for SUI classification:0type：0case；Ⅰtype：8cases； Ⅰ Atype：23cases； Ⅰ Btype：6cases；Ⅲtpye：23cases.49cases (81.67%) were of cystocele, of which35cases were of grade Ⅰ,10cases ofgrade Ⅰ, and4cases of grade Ⅲ;8cases (13.34%) were of uterine prolapse, of which5cases were of grade Ⅰ,3cases of grade Ⅰ,0cases of gradeⅢ;15cases (25%) were ofrectal prolapse, of which10cases were of grade Ⅰ,2cases of grade Ⅰ,3cases of grade Ⅲ;6cases were of enterocele, of which3cases were associated with rectocele;20cases(33.34%) were of descending perineal syndrome.3. Measured parameters of Pelvic floor dynamic MRI, statistical analysis ofurodynamic parameters: the length of H line and M line lengths were positively correlatedwith the size of urethral angle, respectively; the length of H line and M line were positivelycorrelated with the distance of bladder neck across PCL, the distance of cervix across PCL,the distance of anorectal junction across PCL, respectively; the length of H line and M linewere negatively correlated with functional urethral length, Valsalva leak point pressure,maximum urethral closure pressure, and detrusor opening pressure, respectively; the lengthof H line and M line were of no statistical correlation with other urodynamic parameters.4. Kappa test of consistency of POP-Q and dynamic MRI diagnosis on pelvic organprolapse: the consistency of pelvic floor dynamic MRI and POP-Q on the diagnosis ofpelvic organ prolapse in anterior and middle compartment was good, while the consistencyof the two methods on the diagnosis of pelvic organ prolapse in posterior compartment wasrelatively poor. Conclusions:1. Pelvic floor dynamic MRI can directly display the anatomy abnormalities ofpatients with female stress urinary incontinence, and combined with urodynamics it canindirectly reflect the function abnormalities of urethral sphincter closure system.2. Pelvic dynamic MRI combined with urodynamic study have more advantage thanvideo-urodynamics (VUD) study to a certain extent, and can diagnose and classify SUI, toassist in identifying whether it is a SUI with Intrinsic sphincter deficiency (ISD).3. Pelvic floor dynamic MRI can fully assess the conditions of patients of female stressurinary incontinence combined with pelvic organ prolapse.4. The levator ani muscle are the primary contributors to urinary continence andsupport of pelvic organs. Pelvic floor support system and urethral sphincter closure systemabnormalities can exist simultaneously in most of the patients with female stress urinaryincontinence.