title: Performance of 3-dimensional echocardiography in measuring left ventricular volumes and ejection fraction: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The primary aim of this systematic review is to objectively evaluate the test performance characteristics of three-dimensional echocardiography (3DE) in measuring left ventricular (LV) volumes and ejection fraction (EF).
  
  
  BACKGROUND
  Despite its growing use in clinical laboratories, the accuracy of 3DE has not been studied on a large scale. It is unclear if this technology offers an advantage over traditional two-dimensional (2D) methods.
  
  
  METHODS
  We searched for studies that compared LV volumes and EF measured by 3DE and cardiac magnetic resonance (CMR) imaging. A subset of those also compared standard 2D methods with CMR. We used meta-analyses to determine the overall bias and limits of agreement of LV end-diastolic volume (EDV), end-systolic volume (ESV), and EF measured by 3DE and 2D echocardiography (2DE).
  
  
  RESULTS
  Twenty-three studies (1,638 echocardiograms) were included. The pooled biases ± 2 SDs for 3DE were -19.1 ± 34.2 ml, -10.1 ± 29.7 ml, and - 0.6 ± 11.8% for EDV, ESV, and EF, respectively. Nine studies also included data from 2DE, where the pooled biases were -48.2 ± 55.9 ml, -27.7 ± 45.7 ml, and 0.1 ± 13.9% for EDV, ESV, and EF, respectively. In this subset, the difference in bias between 3DE and 2D volumes was statistically significant (p = 0.01 for both EDV and ESV). The difference in variance was statistically significant (p < 0.001) for all 3 measurements.
  
  
  CONCLUSIONS
  Three-dimensional echocardiography underestimates volumes and has wide limits of agreement, but compared with traditional 2D methods in these carefully performed studies, 3DE is more accurate for volumes and more precise in all 3 measurements.
authors.affiliation: Division of Cardiology, School of Medicine, University of Colorado Denver, Aurora, Colorado 80045, USA. Jennifer.Dorosz@ucdenver.edu
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Dorosz
authors.forename: Dennis C
authors.initials: DC
authors.lastname: Lezotte
authors.forename: David A
authors.initials: DA
authors.lastname: Weitzenkamp
authors.forename: Larry A
authors.initials: LA
authors.lastname: Allen
authors.forename: Ernesto E
authors.initials: EE
authors.lastname: Salcedo
mesh_terms: D000818:Animals; D019560:Echocardiography, Three-Dimensional / Q000379:methods / Q000592:standards*; D006801:Humans; D013318:Stroke Volume / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology*