title: Clinical validation of a novel speckle-tracking-based ejection fraction assessment method.
abstract: BACKGROUND
  The aim of this study was to determine the feasibility, accuracy, and reproducibility of a novel tracking-based echocardiographic ejection fraction (EF) assessment method in comparison with traditional methods based on magnetic resonance imaging and echocardiography.
  
  
  METHODS
  In a prospective assessment, apical echocardiographic grayscale image loops from 81 patients were read in random order by four experienced readers, blinded to any data of the cases. In three separate sessions, EFs were estimated using biplane tracking-based assessment and according to the modified Simpson's rule, as well as by visual interpretation in three apical views. Data were compared with a reference EF derived from echocardiography and magnetic resonance imaging.
  
  
  RESULTS
  On average, no significant difference was found between EF estimates of the different methods. Tracking-based EF assessments were possible in 90% of the patients. Tracking-based EF assessments showed slightly higher deviations from the reference EF than the modified Simpson's rule, while interobserver and intraobserver variability of tracking-based assessment were significantly better. Visual interpretation allowed the fastest EF assessment. Tracking-based EF assessment was approximately twice as fast as the modified Simpson's rule.
  
  
  CONCLUSIONS
  Tracking-based EF assessment is feasible, has lower interobserver and intraobserver variability, and is faster than traditional echocardiographic EF quantification. Its minimal demand on user interaction makes it a favorable alternative to traditional echocardiographic approaches, with a particular clinical advantage when reliable follow-up measurements are needed.
authors.affiliation: Department of Cardiovascular Diseases, University Hospital Gasthuisberg, Catholic University Leuven, Leuven, Belgium.
authors.forename: Mariola
authors.initials: M
authors.lastname: Szulik
authors.forename: Christos J
authors.initials: CJ
authors.lastname: Pappas
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Jurcut
authors.forename: Michael
authors.initials: M
authors.lastname: Magro
authors.forename: Elke
authors.initials: E
authors.lastname: Peeters
authors.forename: Kaatje
authors.initials: K
authors.lastname: Goetschalckx
authors.forename: Frank
authors.initials: F
authors.lastname: Rademakers
authors.forename: Walter
authors.initials: W
authors.lastname: Desmet
authors.forename: Jens-Uwe
authors.initials: JU
authors.lastname: Voigt
mesh_terms: D004452:Echocardiography / Q000379:methods*; D005240:Feasibility Studies; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D015588:Observer Variation; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D013318:Stroke Volume / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology*