title: Accuracy and interobserver concordance of echocardiographic assessment of right ventricular size and systolic function: a quality control exercise.
abstract: BACKGROUND
  Accurate assessment of right ventricular (RV) size (RVS) and RV systolic function (RVSF) is vital in the management of various conditions, but their assessment is challenging using echocardiography. The aim of this study was to determine the accuracy and interobserver concordance of qualitative and quantitative RV echocardiography.
  
  
  METHODS
  Fifteen readers evaluated RV function in 12 patients (360 readings) who underwent echocardiography and cardiac magnetic resonance for RV assessment. Readers qualitatively estimated RVS and RVSF as normal, mild, moderate, or severe and then reassessed quantitatively by adding RV dimensions, fractional area change, S', tricuspid annular plane systolic excursion, and RV index of myocardial performance. Cardiac magnetic resonance was used as the reference standard for grading RVS and RVSF.
  
  
  RESULTS
  Quantitative measurements increased accuracy and interreader agreement compared to qualitative assessment alone, especially in normal categories. Readers' accuracy for diagnosing normal and severe RVS increased from 38% to 78% (P = .001) and from 70% to 97% (P = .018), and readers' accuracy for diagnosing normal and mild RVSF increased from 52% to 84% (P < .001) and from 36% to 56% (P = .001). Interreader agreement for classification of the subjects as normal or abnormal improved from a κ value of 0.40 to 0.77 (fair to good agreement) for RVS and from 0.43 to 0.66 (moderate to good agreement) for RVSF.
  
  
  CONCLUSIONS
  Visual estimation of RVS and RVSF is inaccurate and has wide interobserver variability. Quantitation improves accuracy and reliability, especially in distinction of normal and abnormal. The reliability of mild and moderate grades remains inadequate, and further guidance is needed for the classification of abnormal categories.
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Lee Fong
authors.initials: LF
authors.lastname: Ling
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Obuchowski
authors.forename: Leonardo
authors.initials: L
authors.lastname: Rodriguez
authors.forename: Zoran
authors.initials: Z
authors.lastname: Popovic
authors.forename: Deborah
authors.initials: D
authors.lastname: Kwon
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
mesh_terms: D004452:Echocardiography / Q000379:methods* / Q000592:standards*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D009820:Ohio / Q000453:epidemiology; D009929:Organ Size; D011785:Quality Assurance, Health Care; D011786:Quality Control; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging*