title: Evaluation of knowledge-based reconstruction for magnetic resonance volumetry of the right ventricle in tetralogy of Fallot.
abstract: BACKGROUND
  Cardiac magnetic resonance using the Simpson method is the gold standard for right ventricular volumetry. However, this method is time-consuming and not without sources of error. Knowledge-based reconstruction is a novel post-processing approach that reconstructs the right ventricular endocardial shape based on anatomical landmarks and a database of various right ventricular configurations.
  
  
  OBJECTIVE
  To assess the feasibility, accuracy and labor intensity of knowledge-based reconstruction in repaired tetralogy of Fallot (TOF).
  
  
  METHODS
  The short-axis cine cardiac MR datasets of 35 children and young adults (mean age 14.4 ± 2.5 years) after TOF repair were studied using both knowledge-based reconstruction and the Simpson method. Intraobserver, interobserver and inter-method variability were assessed using Bland-Altman analyses.
  
  
  RESULTS
  Knowledge-based reconstruction was feasible and highly accurate as compared to the Simpson method. Intra- and inter-method variability for knowledge-based reconstruction measurements showed good agreement. Volumetric assessment using knowledge-based reconstruction was faster when compared with the Simpson method (10.9 ± 2.0 vs. 7.1 ± 2.4 min, P < 0.001).
  
  
  CONCLUSIONS
  In patients with repaired tetralogy of Fallot, knowledge-based reconstruction is a feasible, accurate and reproducible method for measuring right ventricular volumes and ejection fraction. The post-processing time of right ventricular volumetry using knowledge-based reconstruction was significantly shorter when compared with the routine Simpson method.
authors.affiliation: The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Ave., Toronto, M5G 1X8, Canada.
authors.forename: Emile Christian Arie
authors.initials: EC
authors.lastname: Nyns
authors.forename: Andreea
authors.initials: A
authors.lastname: Dragulescu
authors.forename: Shi-Joon
authors.initials: SJ
authors.lastname: Yoo
authors.forename: Lars
authors.initials: L
authors.lastname: Grosse-Wortmann
mesh_terms: D000293:Adolescent; D005240:Feasibility Studies; D005260:Female; D006352:Heart Ventricles / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D051188:Knowledge Bases; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D015588:Observer Variation; D009929:Organ Size; D011182:Postoperative Care / Q000379:methods; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013771:Tetralogy of Fallot / Q000601:surgery*