title: Real-time simultaneous triplane contrast echocardiography gives rapid, accurate, and reproducible assessment of left ventricular volumes and ejection fraction: a comparison with magnetic resonance imaging.
abstract: OBJECTIVE
  We sought to compare the feasibility, accuracy, and reproducibility of simultaneous triplane echocardiography for measurements of left ventricular (LV) volumes and ejection fraction (EF) with reference to magnetic resonance imaging (MRI).
  
  
  METHODS
  Digital echocardiography recordings of apical LV views with and without intravenous contrast were collected from 53 consecutive patients with conventional 2-dimensional (2D) imaging and with simultaneous triplane imaging. MRI of multiple LV short-axis sections was performed with a 1.5-T scanner. Endocardial borders were manually traced, and LV volumes and EF from 2D biplane echocardiography and MRI were calculated by method of disks. On triplane data, a triangular mesh was constructed by 3-dimensional interpolation and volumes calculated by the divergence theorem.
  
  
  RESULTS
  Triplane image acquisition was less time-consuming than 2D biplane. Precontrast feasibility was 72% for triplane and 82% for 2D biplane images, increasing to 98% and 100% with contrast, respectively. Bland-Altman analysis demonstrated LV volume underestimation by echocardiography versus MRI, which was significantly reduced by contrast and triplane imaging. The 95% limits of agreement for EF between echocardiography and MRI narrowed using triplane compared with 2D biplane (precontrast -12.5 to 6.7% vs -17.2 to 9.9%, and with contrast -7.1 to 5.8% vs -9.4 to 6.4%, respectively). At intraobserver and interobserver analysis of 20 patients, limits of agreement for EF narrowed with contrast triplane compared with 2D biplane.
  
  
  CONCLUSIONS
  Simultaneous LV triplane imaging is feasible with simple and rapid image acquisition and volume analysis, and with contrast enhancement it gives accurate and reproducible LV EF measurements compared with MRI.
authors.affiliation: Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. siri.malm@ntnu.no
authors.forename: Siri
authors.initials: S
authors.lastname: Malm
authors.forename: Sigmund
authors.initials: S
authors.lastname: Frigstad
authors.forename: Einar
authors.initials: E
authors.lastname: Sagberg
authors.forename: Per Arvid
authors.initials: PA
authors.lastname: Steen
authors.forename: Terje
authors.initials: T
authors.lastname: Skjarpe
mesh_terms: D003199:Computer Systems; D004452:Echocardiography / Q000379:methods*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000473:pathology