The anatomy of stress incontinence: magnetic resonance imaging of the female bladder neck and urethra.

Clinical, urodynamic, radiological and endoscopic evaluations as well as operative results on more than 800 cases of stress incontinence treated at our medical center have led to a better understanding of the pathophysiology of female stress incontinence. We attempt to correlate these physiological concepts with information obtained from magnetic resonance images of the paraurethral and bladder neck areas in patients with known stress incontinence and normal controls. All magnetic resonance images were compared to cadaver step sections of the female pelvis. Normal controls without stress incontinence were used to define normal anatomy by magnetic resonance imaging. Etiology of incontinence was divided into either intrinsic urethral damage or anatomical malposition of an intact sphincteric unit. Our findings not only provide valuable support to basic concepts of the pathophysiology of stress incontinence but also help to establish normal findings of female paraurethral and bladder neck anatomy as seen by magnetic resonance imaging.