MRI morphology of the levator ani muscle, endopelvic fascia, and urethra in women with stress urinary incontinence

Abstract

Objective To evaluate pathomorphologic changes of the levator ani muscle, endopelvic fascia, and urethra in women with stress urinary incontinence (SUI) by MRI. Study design Fifty-four women with SUI were examined by MRI (1.5 T): body phased-array coil, axial and coronal proton-density-weighted sequences. Results The urethral sphincter muscle showed a reduced thickness of its posterior portion (37%), an omega shape (13%) or higher signal intensity (50%); its abnormal configuration was associated with an increased signal intensity in 70% ( p = 0.001). The levator ani muscle comprised an unilateral loss of substance in 30%, a higher signal intensity in 28%, and alterated origin in 19%. Central defects of the endopelvic fascia were present in 39% ( n = 21), lateral defects in 46%. There was a significant association between loss of the symphyseal concavity of the anterior vaginal wall and lateral fascial defects ( p = 0.001) and levator ani changes ( p = 0.016). Conclusion MRI yields findings supporting current theories on the pathogenesis of SUI.