title: Assessment of levator ani morphology and function in asymptomatic nulliparous women via static and dynamic magnetic resonance imaging.
abstract: OBJECTIVE
  To evaluate levator ani morphology and function in healthy nulliparous women using static and dynamic magnetic resonance imaging.
  
  
  METHODS
  Eighty asymptomatic, healthy nulliparous Chinese women (mean age, 25.3±3.5years) volunteered for the present study. Static T2-weighted fast spin-echo images were employed to evaluate levator ani morphology; dynamic T2-weighted fast imaging employing steady-state acquisition was used to evaluate its function. A 2 samples t test was employed to compare groups.
  
  
  RESULTS
  No morphologic abnormality was detected in the 80 healthy nulliparous women. However, 15% (12/80) of women had various degrees of pelvic organ descent below the pubococcygeal line. In these women, the width of the pubic portion of the levator ani was significantly reduced during straining, whereas the levator plate angle, the levator hiatus area, and the H and M line lengths were enlarged. These changes were associated with weakened levator ani function and pelvic floor laxity.
  
  
  CONCLUSIONS
  Functional abnormality of the levator ani muscle was noted in nulliparous women at static and dynamic magnetic resonance imaging. Further follow-up investigation is needed to confirm whether women with functional abnormality are more likely to develop a prolapse after vaginal birth.
authors.affiliation: Medical Imaging Center, First Affiliated Hospital, Jinan University, Guangzhou, China.
authors.forename: Xiang-Ran
authors.initials: XR
authors.lastname: Cai
authors.forename: Lin
authors.initials: L
authors.lastname: Qiu
authors.forename: He-Jia
authors.initials: HJ
authors.lastname: Wu
authors.forename: Si-Run
authors.initials: SR
authors.lastname: Liu
mesh_terms: D000328:Adult; D002681:China; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009130:Muscle, Smooth / Q000473:pathology / Q000502:physiology*; D017773:Pelvic Floor / Q000473:pathology / Q000502:physiology*; D055815:Young Adult