The contribution of magnetic resonance imaging of the pelvic floor to the understanding of urinary incontinence.

The anatomy of urinary incontinence and the underlying pathology is still under discussion. We examined 24 stress incontinent patients and 6 healthy volunteers. Magnetic resonance imaging (MRI) clearly shows that the urethra is not connected to the levator ani. The urethra is not fixed to deep perineal muscle layers. In stress incontinence the sharp angulation of the levator ani of healthy volunteers is lost in 65%. MRI shows degeneration of the levator ani muscle in 45% of stress incontinent patients. The extent of damage to the levator can clearly be identified with the aid of MRI.