title: Pelvic floor muscle injuries 6 weeks post partum-an intra- and inter-rater study.
abstract: OBJECTIVE
  To evaluate intra- and inter-rater reliability when diagnosing major defects, and inter-rater reliability of diagnosing minor defects and muscle thickness of the pubovisceral muscle in primiparous women 6 weeks after vaginal delivery, using 3D/4D transperineal ultrasound.
  
  
  METHODS
  Forty primiparous women were assessed using 3D/4D transperineal ultrasound. Volumes were acquired at maximal pelvic floor muscle (PFM) contraction, and diagnosis of muscle defects were done using tomographic ultrasound imaging (TUI) of the axial plane. Thickness was measured in three central levels of TUI. The stored volumes were analyzed offline by two investigators blinded to each others' results and the women's clinical data. Cohen's kappa (κ) and percentual agreement were calculated for defects, intraclass correlations coefficient (ICC) with 95% confidence intervals were calculated for thickness.
  
  
  RESULTS
  Excellent intra-rater values were found for all major defects. Inter-rater values for bilateral and right-sided defects were excellent, and good for left-sided. Agreement for minor defects was poor. Measuring thickness ICC of 0.72 was found for the left side and 0.48 for the right side, although up to half of the cases had to be excluded owing to poor demarcation of the muscle.
  
  
  CONCLUSIONS
  Tomographic ultrasound imaging of the axial plane using three central slices seems to be a reliable tool for detecting major pubovisceral muscle defects shortly after childbirth. Minor defects showed low reliability. Muscle thickness measurements showed moderate reliability, but too many cases had to be excluded for this to be a useful method for determining muscle thinning 6 weeks after delivery.
authors.affiliation: Department of Obstetrics and Gynaecology, Akershus University Hospital, Lørenskog, Norway. jett@ahus.no
authors.forename: Jette
authors.initials: J
authors.lastname: Staer-Jensen
authors.forename: Franziska
authors.initials: F
authors.lastname: Siafarikas
authors.forename: Gunvor
authors.initials: G
authors.lastname: Hilde
authors.forename: Ingeborg H
authors.initials: IH
authors.lastname: Braekken
authors.forename: Kari
authors.initials: K
authors.lastname: Bø
authors.forename: Marie Ellström
authors.initials: ME
authors.lastname: Engh
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D009119:Muscle Contraction; D015588:Observer Variation; D017773:Pelvic Floor / Q000000981:diagnostic imaging* / Q000503:physiopathology; D059952:Pelvic Floor Disorders / Q000000981:diagnostic imaging* / Q000503:physiopathology; D049590:Postpartum Period; D011237:Predictive Value of Tests; D011247:Pregnancy; D015203:Reproducibility of Results; D013997:Time Factors; D014463:Ultrasonography
keywords: inter-rater reliability; muscle thinning; pelvic floor; pubovisceral muscle defect; transperineal ultrasound