title: Reproducibility of right ventricular volumes and ejection fraction using real-time three-dimensional echocardiography: comparison with cardiac MRI.
abstract: OBJECTIVE
  The nongeometric nature of the right ventricle (RV) makes it difficult to measure. We sought to determine whether real-time three-dimensional echocardiography (RT3DE) is superior to two-dimensional echocardiography (2DE) for the follow-up of RV function by validation vs cardiac MRI.
  
  
  METHODS
  RV volumes and ejection fraction (EF) were studied with 2DE (including area-length [A-L], the modified two-dimensional subtraction [2DS] method, and the Simpson method of discs), RT3DE, and MRI in 50 patients with left ventricular wall motion abnormalities, the results of which suggested possible RV infarction. Test-retest variation was performed by a complete restudy using a separate sonographer within 24 h without the alteration of hemodynamics or therapy. Interobserver and intraobserver variations were noted in a subgroup of 20 patients.
  
  
  RESULTS
  EF estimations were similar using each technique. The mean (+/- SD) MRI end-diastolic volume (87 +/- 22 mL) was only slightly underestimated by RT3DE (mean difference, -3 +/- 10; p < 0.05), with a greater mean difference for 2DE A-L (-29 +/- 10; p < 0.05), and the Simpson method of discs (-29 +/- 23; p < 0.05), and was greatly overestimated by 2DS (mean difference, 26 +/- 23; p < 0.05). Similarly, the mean MRI end-systolic volume (46 +/- 17 mL) was only slightly underestimated by RT3DE (-4 +/- 7; p < 0.05), compared with 2DE A-L (-16 +/- 8; p < 0.05) and the Simpson method of discs (-16 +/- 8; p < 0.05), and was overestimated by 2DS (14 +/- 13; p < 0.05). RT3DE findings had a higher correlation with each parameter than any 2DE technique. There was also good intraobserver and interobserver correlation between RT3DE by two sonographers. RT3DE had less test-retest variation of RV volumes and EF than any 2DE measure.
  
  
  CONCLUSIONS
  RT3DE is more accurate than two-dimensional approaches and reduces the test-retest variation of RV volumes and EF measurements in follow-up RV assessment.
authors.affiliation: University of Queensland, QLD, Australia.
authors.forename: Carly
authors.initials: C
authors.lastname: Jenkins
authors.forename: Jonathan
authors.initials: J
authors.lastname: Chan
authors.forename: Kristen
authors.initials: K
authors.lastname: Bricknell
authors.forename: Mark
authors.initials: M
authors.lastname: Strudwick
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
mesh_terms: D000368:Aged; D003199:Computer Systems; D004452:Echocardiography; D019560:Echocardiography, Three-Dimensional; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D013318:Stroke Volume / Q000502:physiology*