MR imaging of the female pelvic floor in the supine and upright positions

Abstract

The goal of this study was to determine whether a .5-T open configuration magnet system could be used to evaluate the female pelvic floor support structures and their functional changes in the upright and supine positions. We evaluated five normal volunteers with full bladders in the supine and sitting positions. Multiple measurements were obtained, including distance between symphysis and urethra, bladder neck to fixed pubococcygeal line, and posterior urethrovesical angle. The pelvic floor was evaluated for integrity of the urethra, vagina, and supporting ligaments. High quality, interpretable images were obtained for all five patients in both positions. Most of the pelvic floor structures were stable, with the exception of the posterior urethrovesical angle, which increased in the sitting position. We conclude that the vertically open configuration magnet system shows promise for evaluation of the female pelvic floor, including urinary stress incontinence and prolapse.

Traction force needed to reproduce physiologically observed uterine movement: technique development, feasibility assessment, and preliminary findings

“…Strengths of our methods include the use of a custom-designed computer-controlled servoactuator device able to make highly accurate force-displacement measurements, as well as the use of well-developed MRI strategies for quantifying physiological movements. It would be ideal to perform these studies in the standing posture, but at the present time, this has not been feasible, and comparison of upright and supine images of the pelvic floor do not show major differences [15]. Additionally, our technique using dynamic stress MRI to assess physiologic uterine movement allows for precise imaging and measurement of uterine location without instrumentation of the vagina.…”

Quantification of abdominal and pelvic floor muscle synergies in response to voluntary pelvic floor muscle contractions

“…Therefore, when attempting to prevent urine leakage the PFMs should presumably have to work harder in sitting and standing, anti-gravity positions, than in supine, a gravity eliminated position. Magnetic resonance imaging evidence by Fielding et al indicated that in five continent women the angles between the urethra and the bladder base were the same in supine and standing but greater in sitting (Fielding et al, 1996). An increase in the angle between the bladder base and the urethra is seen during micturition (DeLancey, 1990), and a larger resting angle induced posturally or otherwise may therefore contribute to leakage in women with SUI.…”

Static magnetic resonance imaging of the pelvic floor muscle morphology in women with stress urinary incontinence and pelvic prolapse

“…Comparative studies of anatomic preparations and healthy subjects yielded a more precise picture of the topographic and functional anatomy of the pelvic floor in vivo and provided a basis for standardized image interpretation [Invanov et al, 1992;Christensen et al, 1995;Klutke and Siegel, 1995;Strohbehn et al, 1996a]. Numerous reports were published on the analysis and limits of dynamic MRI [Yang et al, 1991;Ozasa et al, 1992;Ghoniem et al, 1992;Goodrich et al, 1993;Ivanov et al, 1993;Fielding et al, 1996;Healy et al, 1997].…”