title: Automated quantification of mitral regurgitation by three dimensional real time full volume color Doppler transthoracic echocardiography: a validation with cardiac magnetic resonance imaging and comparison with two dimensional quantitative methods.
abstract: BACKGROUND
  Accurate assessment of mitral regurgitation (MR) severity is crucial for clinical decision-making and optimizing patient outcomes. Recent advances in real-time three dimensional (3D) echocardiography provide the option of real-time full volume color Doppler echocardiography (FVCD) measurements. This makes it practical to quantify MR by subtracting aortic stroke volume from the volume of mitral inflow in an automated manner.
  
  
  METHODS
  Thirty-two patients with more than a moderate degree of MR assessed by transthoracic echocardiography (TTE) were consecutively enrolled during this study. MR volume was measured by 1) two dimensional (2D) Doppler TTE, using the proximal isovelocity surface area (PISA) and the volumetric quantification methods (VM). Then, 2) real time 3D-FVCD was subsequently obtained, and dedicated software was used to quantify the MR volume. MR volume was also measured using 3) phase contrast cardiac magnetic resonance imaging (PC-CMR). In each patient, all these measurements were obtained within the same day. Automated MR quantification was feasible in 30 of 32 patients.
  
  
  RESULTS
  The mean regurgitant volume quantified by 2D-PISA, 2D-VM, 3D-FVCD, and PC-CMR was 72.1 ± 27.7, 79.9 ± 36.9, 69.9 ± 31.5, and 64.2 ± 30.7 mL, respectively (p = 0.304). There was an excellent correlation between the MR volume measured by PC-CMR and 3D-FVCD (r = 0.85, 95% CI 0.70-0.93, p < 0.001). Compared with PC-CMR, Bland-Altman analysis for 3D-FVCD showed a good agreement (2 standard deviations: 34.3 mL) than did 2D-PISA or 2D-VM (60.0 and 62.8 mL, respectively).
  
  
  CONCLUSIONS
  Automated quantification of MR with 3D-FVCD is feasible and accurate. It is a promising tool for the real-time 3D echocardiographic assessment of patients with MR.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Korea.
authors.forename: Jang-Won
authors.initials: JW
authors.lastname: Son
authors.forename: Hyuk-Jae
authors.initials: HJ
authors.lastname: Chang
authors.forename: Jin-Kyung
authors.initials: JK
authors.lastname: Lee
authors.forename: Hee-Jung
authors.initials: HJ
authors.lastname: Chung
authors.forename: Ran-Young
authors.initials: RY
authors.lastname: Song
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Kim
authors.forename: Saurabh
authors.initials: S
authors.lastname: Datta
authors.forename: Ran
authors.initials: R
authors.lastname: Heo
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Shin
authors.forename: In-Jeong
authors.initials: IJ
authors.lastname: Cho
authors.forename: Chi Young
authors.initials: CY
authors.lastname: Shim
authors.forename: Geu-Ru
authors.initials: GR
authors.lastname: Hong
authors.forename: Namsik
authors.initials: N
authors.lastname: Chung
keywords: 3D echocardiography; Mitral regurgitation; Quantitative evaluation