title: Assessment of myocardial perfusion by dynamic O-15-labeled water PET imaging: validation of a new fast factor analysis.
abstract: BACKGROUND
  Factor analysis (FA) is an established method for separating myocardium from blood pool by use of oxygen 15-labeled water and positron emission tomography for analyzing myocardial blood flow (MBF). Conventional FA methods generating images from sinograms (sinoFA) are time-consuming, whereas FA can be performed on the reconstructed images (reconFA) in a fraction of time. We validated the MBF values obtained by reconFA versus sinoFA.
  
  
  RESULTS
  In 23 volunteers (mean age, 26.6 +/- 3.4 years) MBF was calculated from sinoFA and reconFA and blindly reanalyzed 1 month later by the same observer. Intraobserver agreement and reconFA-versus-sinoFA agreement were assessed according to Bland and Altman (BA). Reproducibility proved excellent for global sinoFA (r = 0.968; P < .001; BA limits, -0.617 to 0.676 mL x min(-1) x g(-1)) and slightly superior for reconFA (r = 0.979; P < .001; BA limits, -0.538 to 0.558 mL x min(-1) x g(-1)), with wider limits of agreement for segmental MBF from sinoFA (r = 0.777; P < .001; BA limits, -1.676 to 1.656 mL x min(-1) x g(-1)) and reconFA (r = 0.844; P < .001; BA limits, -1.999 to 1.992 mL x min(-1) x g(-1)). In addition, sinoFA and reconFA showed excellent correlation (r = 0.975, P < .001) and agreement (BA limits, -0.528 to 0.648 mL x min(-1) x g(-1)) for global and segmental values (r = 0.955; P < .001; BA limits, -1.371 to 1.491 mL x min(-1) x g(-1)).
  
  
  CONCLUSIONS
  Use of reconFA allows rapid and reliable quantitative MBF assessment with O-15-labeled water.
authors.affiliation: Department of Medical Radiology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Itaru
authors.initials: I
authors.lastname: Adachi
authors.forename: Oliver
authors.initials: O
authors.lastname: Gaemperli
authors.forename: Ines
authors.initials: I
authors.lastname: Valenta
authors.forename: Tiziano
authors.initials: T
authors.lastname: Schepis
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Siegrist
authors.forename: Valerie
authors.initials: V
authors.lastname: Treyer
authors.forename: Cyrill
authors.initials: C
authors.lastname: Burger
authors.forename: Koichi
authors.initials: K
authors.lastname: Morita
authors.forename: Philipp A
authors.initials: PA
authors.lastname: Kaufmann
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014867:Water