title: Reliability of manual and semi-automated measurements of nuchal translucency by experienced operators.
abstract: OBJECTIVE
  To compare intra-/inter-operator reliability of manual and semi-automated NT measurement by experienced operators.
  
  
  METHODS
  Images of 103 fetuses at 11 to 13+6weeks were selected. Two operators performed NT measurement independently 3 times each using both manual and semi-automated methods. Intraoperator reliability of the methods was evaluated using ICCs; interoperator reliability was assessed via correlation between the means of the 3 measurements of each operator. Agreement between the 2 methods was evaluated via Bland-Altman plot.
  
  
  RESULTS
  ICCs for the manual method were 0.80 (95% CI, 0.73-0.85) for operator 1 and 0.82 (95% CI, 0.76-0.87) for operator 2; ICCs for the semi-automated method were 0.80 (95% CI, 0.74-0.85) for operator 1 and 0.82 (95% CI, 0.76-0.86) for operator 2. Interoperator reliability for both methods was high: correlation coefficients 0.91 (95% CI, 0.87-0.94) and 0.96 (95% CI, 0.94-0.97) for manual and semi-automated methods, respectively. Mean NT measured by manual and semi-automated methods was 1.15mm and 1.28mm, respectively (P<0.001). Agreement between the methods was good.
  
  
  CONCLUSIONS
  The reliability of semi-automated NT measurements was comparable to that of the manual method. The new method was reproducible and may be used instead of the manual method in the normal range of NT.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand. nin056@hotmail.com
authors.forename: Ninlapa
authors.initials: N
authors.lastname: Pruksanusak
authors.forename: Savitree
authors.initials: S
authors.lastname: Pranpanus
authors.forename: Chitkasaem
authors.initials: C
authors.lastname: Suwanrath
authors.forename: Ounjai
authors.initials: O
authors.lastname: Kor-anantakul
authors.forename: Thitima
authors.initials: T
authors.lastname: Suntharasaj
authors.forename: Tharangrut
authors.initials: T
authors.lastname: Hanprasertpong
authors.forename: Tippawan
authors.initials: T
authors.lastname: Liabsuetrakul
mesh_terms: D001331:Automation / Q000379:methods*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D048208:Nuchal Translucency Measurement / Q000379:methods*; D015588:Observer Variation; D011247:Pregnancy; D015203:Reproducibility of Results