Dynamic magnetic resonance imaging of the pelvic floor in patients with idiopathic combined fecal and urinary incontinence

The etiologies of combined fecal and urinary incontinence may be interrelated but remain poorly understood. A potential variable in this process is global pelvic floor dysfunction. The aim of this study was to prospectively assess the use of phased-array, body coil dynamic MRI in identifying pelvic floor abnormalities in patients with combined incontinence symptoms. Symptomatic patients were compared to asymptomatic control subjects and were selected from those referred to the pelvic physiology laboratory with complaints of combined urinary and fecal incontinence. All patients underwent standard urodynamic studies and anorectal physiologic assessment. Colonoscopy and endoanal ultrasonography were also performed. A standardized protocol was used for dynamic MRI, and the parameters were measured using workstation software (callipers, compass, and densitometer). In the incontinent group there was a significant difference, when compared to control subjects, in the angle of the levator ani muscle arch of the levator plate complex (3.0 ± 5 degrees vs. 14 ± 10 degrees; P = 0.004), the width of the levator hiatus (58.3 ± 8 mm vs. 46.5 ± 8 mm; P = 0.001), the area and tissue density of the levator ani muscle (19.5 ±1 mm² vs. 26.9 ±1 mm²; P = 0.001, and 157.3 ± 47 pixels vs. 126.1 ± 23 pixels; P ± 0.025, respectively), and in the length of the external anal sphincter (20.0 ± 5 mm vs. 26.6 ± 13 mm; P = 0.03). Body coil dynamic MRI is a noninvasive and well-tolerated imaging modality. Our data show that it can identify changes in pelvic muscle morphology in patients with disorders of incontinence, and this may help in planning better management strategies. Presented at the Forty-Fourth Annual Meeting of The Society for Surgery of the Alimentary Tract, Orlando, Florida, May 18–21, 2003 (oral presentation), and the Eighteenth Annual SSAT Residents and Fellows Research Conference, Orlando, Florida, May 17, 2003.