title: Accuracy of commercially available processing algorithms for planar radionuclide ventriculography using data for a dynamic left ventricular phantom.
abstract: BACKGROUND
  Automatic and semi-automatic algorithms to calculate ejection fraction (EF) from planar radionuclide ventriculography (PRV) have been used for many years in nuclear medicine. Validation of these algorithms is scarce and often performed on outdated versions of the software. Nevertheless, clinical trials where PRV is being used as the 'gold standard' for EF are numerous. Because of the importance attributed to the EF calculated by these programs, the accuracy of the resulting EF was assessed with a dynamic left ventricular physical phantom.
  
  
  METHODS
  A dynamic left ventricular phantom was used to simulate 21 combinations of various ejection fractions (7-66%) and end diastolic volumes (27-290 ml). For each combination, a planar radionuclide ventriculograph was acquired, converted to an interfile format and transferred into processing stations with 10 different contemporaneously available commercial algorithms. The gold standard was the 'real' EF of the phantom, derived from the exact volume of the ventricle in end diastolic and end systolic position. Correlation and Bland-Altman analysis was performed between the real EF and the calculated EF.
  
  
  RESULTS
  The correlation for all data was excellent (r=0.98), the mean difference was very acceptable (0.98%). Nevertheless, Bland-Altman analysis showed a significant trend in the difference between real and calculated EF, with a growing underestimation for higher ranges of EF, due to an overestimation of background in larger volumes compared to smaller ones.
  
  
  CONCLUSIONS
  The determination of EF from PRV, calculated with commercially available algorithms, correlates closely to the real EF of a dynamic left ventricular phantom. This phantom can be used in the development and validation of algorithms for PRV studies, in software audits and in quality assurance procedures.
authors.affiliation: Division of Nuclear Medicine, Ghent University Hospital, Ghent University, K.U. Leuven, Belgium. pdebondt@skynet.be
authors.forename: Pieter
authors.initials: P
authors.lastname: De Bondt
authors.forename: Olivier
authors.initials: O
authors.lastname: De Winter
authors.forename: Stijn
authors.initials: S
authors.lastname: Vandenberghe
authors.forename: Frederic
authors.initials: F
authors.lastname: Vandevijver
authors.forename: Patrick
authors.initials: P
authors.lastname: Segers
authors.forename: Art
authors.initials: A
authors.lastname: Bleukx
authors.forename: Hamphrey
authors.initials: H
authors.lastname: Ham
authors.forename: Pascal
authors.initials: P
authors.lastname: Verdonck
authors.forename: Rudi A
authors.initials: RA
authors.lastname: Dierckx
mesh_terms: D000465:Algorithms; D002986:Clinical Trials as Topic; D004562:Electrocardiography; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D015233:Models, Statistical; D019047:Phantoms, Imaging; D015635:Radionuclide Ventriculography / Q000379:methods*; D015203:Reproducibility of Results; D012984:Software; D013223:Statistics as Topic; D016277:Ventricular Function, Left