Female urinary genuine stress incontinence: anatomic considerations at MR imaging of the paravaginal fascia and urethra initial observations.
OBJECTIVE
To compare, on high-spatial-resolution magnetic resonance (MR) images, the presence and distribution of the paravaginal fascia in continent women and in those with genuine stress incontinence (GSI) to establish its role in the pathophysiology of GSI.


METHODS
Eleven continent reference subjects and 10 GSI patients underwent MR imaging with a specifically designed endovaginal receiver coil. A urinary continence questionnaire and urogynecologic clinical examination had been completed. GSI was diagnosed with urodynamic tests. Paravaginal fascial tissue distribution was determined, and the paravaginal fascial volume (PFV) anteriorly associated with the urethra was measured. Retropubic urethral length (UL) in the supine position at rest was compared with its total length and expressed as a percentage ratio. Comparisons of urethral PFV and retropubic UL between reference subjects and the GSI patients were performed by means of two-sample t tests with unequal variances because data were parametric by means of the Shapiro-Francia W' test for normal data.


RESULTS
The paravaginal fascia (connective tissue that contained venous plexus) was a consistent MR imaging feature in all women. Mean urethral PFV was 5.3 cm(3) +/- 0.6 (SD) in reference subjects compared with 3.5 cm(3) +/- 2.0 in GSI patients (P =.017). The ratio of the retropubic UL to its total length was 82.6% +/- 7.4 in reference subjects compared with 57.4% +/- 9.8 in GSI patients (P <.001). There was a weak correlation between urethral PFV and retropubic UL (r = 0.46).


CONCLUSIONS
There is a significant association between urethral PFV and continence status. GSI patients have a reduced urethral PFV, and greater than 40% of their urethral length lies below the pubis in the supine position at rest. However, the effects of age and hormonal status on urethral PFV remain to be evaluated.
deSouza
Nandita M
NM
Robert Steiner MRI Unit, Faculty of Medicine, Imperial College of Science, Technology and Medicine, Hammersmith Hospital Campus, DuCane Rd, London W12 0HS, England. n.desouza@ic.ac.uk
Daniels
O Joseph
OJ
Williams
Andreanna D
AD
Gilderdale
David J
DJ
Abel
Paul D
PD
D000328:Adult; D000368:Aged; D004867:Equipment Design; D005205:Fascia / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008875:Middle Aged; D012016:Reference Values; D012680:Sensitivity and Specificity; D012984:Software; D014521:Urethra / Q000473:pathology*; D014550:Urinary Incontinence, Stress / Q000175:diagnosis*; D014621:Vagina / Q000473:pathology*; D014680:Veins / Q000473:pathology