title: Rapid and accurate noninvasive assessment of global left ventricular systolic function using biplane advanced automated contour tracking method.
abstract: BACKGROUND
  The advanced automated contour tracking (AACT) method has been newly developed for automated detection of the left ventricular endocardial boundary. Left ventricular ejection fraction (LVEF) may be estimated by applying the AACT method to 2 orthogonal planes of patients even when regional wall-motion abnormalities exist. The purpose of this study was to examine the reliability of the biplane AACT method in the measurement of LVEF in patients with suggested ischemic heart disease with use of quantitative gated single photon emission computed tomography (QGS) as a reference standard.
  
  
  METHODS
  The study population consisted of 47 consecutive patients with suggested ischemic heart disease. All patients underwent 2-dimensional echocardiography and QGS. Biplane LVEF from apical 4- and 2-chamber views was measured offline by the AACT method using disk summation method. The accuracy of the AACT method for LVEF measurement was determined in comparison with QGS.
  
  
  RESULTS
  In 41 (29 with and 12 without regional wall-motion abnormalities) of 47 patients (87%), automated tracing of the endocardial border was adequately achieved with the AACT method. LVEF measured by the AACT method correlated well with that measured by QGS (y = 0.97x +2.4, r = 0.91). The mean difference between AACT and QGS was 0.6 +/- 5.5% (mean +/- SD). The mean time required for analysis of 1 set of images during 1 cardiac cycle by the AACT method was much shorter than that required by manual tracing method (7 +/- 1 vs 37 +/- 4 seconds, P <.0001).
  
  
  CONCLUSIONS
  The biplane AACT method provides accurate and quick measurement of LVEF in patients even with regional wall-motion abnormalities.
authors.affiliation: Department of Internal Medicine and Cardiology, Osaka City University Medical School, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugioka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hozumi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Watanabe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamagishi
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Matsumura
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Takemoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Muro
authors.forename: Minoru
authors.initials: M
authors.lastname: Yoshiyama
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Takeuchi
authors.forename: Junichi
authors.initials: J
authors.lastname: Yoshikawa
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging; D015203:Reproducibility of Results; D013599:Systole / Q000502:physiology*; D015899:Tomography, Emission-Computed, Single-Photon; D014463:Ultrasonography; D016277:Ventricular Function, Left