RESUMO
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 (1.5T): 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 altered 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.