title: Pitfalls of echocardiographic measurement in tissue harmonic imaging: in vitro and in vivo study.
abstract: BACKGROUND
  Tissue harmonic imaging (THI) is a useful method for endocardial border detection by transthoracic echocardiography, especially in technically difficult patients, even though accuracy of this method in the echocardiographic measurement is unclear. The purpose of this study is to evaluate the accuracy of echocardiographic measurement by THI in vivo and in vitro.
  
  
  METHODS
  In vitro, we measured wall thickness, dimension, and volume of the excised hearts by THI. In 11 patients, we assessed the comparative accuracy of THI and fundamental imaging (FI) in determination of left ventricular (LV) wall thickness, dimension, volume, and ejection fraction.
  
  
  RESULTS
  In vitro, thickness measurements by THI overestimated true length, and both volume and dimension measurements by THI underestimated true values. In vivo, LV ejection fraction measurements obtained by THI exhibited excellent correlation and agreement with those obtained by FI. However, LV wall thickness determined by THI was significantly larger than that determined by FI, and the dimensions and volume of LV measured by THI were significantly smaller than those measured by FI.
  
  
  CONCLUSIONS
  Although THI is an excellent imaging technique for determination of LV ejection fraction, echocardiographic measurement by THI underestimates LV dimensions and volume, and overestimates LV wall thickness.
authors.affiliation: Department of Internal Medicine and Cardiology, Osaka City University Medical School, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Hirata
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Watanabe
authors.forename: Shintaro
authors.initials: S
authors.lastname: Beppu
authors.forename: Takashi
authors.initials: T
authors.lastname: Muro
authors.forename: Masakazu
authors.initials: M
authors.lastname: Teragaki
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: D000368:Aged; D000818:Animals; D004452:Echocardiography / Q000145:classification / Q000379:methods*; D004699:Endocardium / Q000000981:diagnostic imaging; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008875:Middle Aged; D013318:Stroke Volume / Q000502:physiology*; D013552:Swine