An evaluation of pelvic floor anatomy and function by MRI.

Objective: In this experimental study, we wanted to evaluate the informative value of dynamic magnetic resonance imaging in pelvic floor anatomy during pelvic floor muscle contractions in asymptomatic women and women with urinary continence dysfunction.

Study Design: Eight outpatients with stress urinary symptoms and eight asymptomatic women were scanned with a 1.5 T GE Signa CV/i high-speed scanner with real time fluorescopic imaging possibilities. The static and dynamic anatomical status of the levator ani muscle was registered.

Results: In sagittal magnetic resonance imaging (MRI) images, the iliococcygeus muscle appeared as dome-shaped at rest. The thickness of the distal part of pubococcygeal muscle correlated significantly with EMG values during a maximal contraction. The most obvious defects seen in the pubococcygeal muscle were asymmetry in thickness and loss of fiber continuity.

Conclusion: Functional and anatomic relationships in the pelvic floor can be demonstrated by the combined use of EMG and MRI, providing a better understanding of the pathophysiological mechanisms behind stress incontinence in women.