A preliminary application of tomographic ultrasound imaging and magnetic resonance imaging in evaluating levtor avulsion in postpartum women

Objective To study the changes of levator-urethra gap (LUG) by tomographic ultrasound imaging (TUI) and levator-symphysis gap (LSG) by magnetic resonance imaging (MRI) in postpartum females. Methods Twenty postpartum women with levator avulsion and 20 nulliparas were examined by TUI and LUGs were measured on the slice 0,1 and 2. Magnetic resonance imaging scans of levator ani muscle were obtained in thin slices. Then a three-dimensional model of the levator ani muscle was created by Mimics software. LSGs were measured on three-dimensional models. Results None levator avulsion were found in the images of 20 nulliparas. LUG was (17.80±1.39) mm and LSG was (19.71±1.94) mm. The levator avulsions were found in 28 sides, and 12 sides were without levator avulsion. The LUG of levator avulsion (27.94±2.53) mm was greater than that of intact levator ani muscle (19.78±1.35) mm, and the difference was statistically significant (t=8.352, P<0.05). The LSG of levator avulsion (37.39±4.11) mm was greater than that of intact levator ani muscle (21.81±2.96) mm, and the difference was statistically significant (t=8.352, P<0.05). Conclusions TUI and MRI are effective examinations to diagnose levator avulsion. LUG and LSG are good imaging parameters to evaluate the levator avulsion in postpartum women. Key words: Ultrasonography; Magnetic resonance imaging; Levator-urethra gap; Levator-symphysis gap