title: Anatomic variations in the levator ani muscle, endopelvic fascia, and urethra in nulliparas evaluated by magnetic resonance imaging.
abstract: OBJECTIVE
  The purpose of this study was to develop a system to quantify interindividual variation in the appearance of continence system structures in normal continent nulliparous women.
  
  
  METHODS
  Magnetic resonance imaging (1.5 T) was performed in 20 healthy continent nulliparous women (mean age, 30.1 +/- 5.1 years) with normal pelvic organ support and urodynamics. Morphometric measurements of the levator ani muscle, endopelvic fascia, and urethra were performed.
  
  
  RESULTS
  The ratio of the maximum-to-minimum measured values shows that 2- to 3-fold differences occur in distance, area, or volume measures of continence system morphologic features. The mean urogenital hiatus area was 15.2 +/- 2.9 cm(2) in women without a visible connection of the levator ani muscle to the pubic bone (4/20 women) and 12.3 +/- 2.4 cm(2) in women with an levator ani muscle-pubic bone connection (16/20 women, P =.05).
  
  
  CONCLUSIONS
  Considerable variation that was not attributable to limitations of the measuring technique that was used occurs in the size and configuration of the urethral support structures in nulliparous asymptomatic women.
authors.affiliation: Department of Obstetrics and Gynecology, Charité Campus Mitte, Humboldt-Universität zu Berlin, Berlin, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Tunn
authors.forename: John O l
authors.initials: JO
authors.lastname: Delancey
authors.forename: Denise
authors.initials: D
authors.lastname: Howard
authors.forename: James A
authors.initials: JA
authors.lastname: Ashton-Miller
authors.forename: Leslie E
authors.initials: LE
authors.lastname: Quint
mesh_terms: D000328:Adult; D005205:Fascia / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D010298:Parity; D017773:Pelvic Floor / Q000033:anatomy & histology*; D014521:Urethra / Q000033:anatomy & histology*