title: C-11 acetate has excellent reproducibility for quantification of myocardial oxidative metabolism.
abstract: OBJECTIVE
  C-11 acetate PET imaging allows quantification of myocardial oxidative metabolism. We sought to assess the reproducibility of such analysis with the Carimas software.
  
  
  RESULTS
  The myocardial oxygen consumption rate was assessed via a kmono index--the clearance rate constant of a mono-exponential function fitted to a C-11 acetate clearance curve. Two observers of different experience levels--a novice and an expert--analysed 53 C-11 acetate PET studies--each study twice. These results were compared using Bland-Altman (BA) plots with the global kmono-s obtained earlier with a validated reference method. We also assessed intra- and interobserver reproducibility on global, regional, and segmental [17-segment model (AHA)] levels--a linear mixed model for the repeated measures was fitted to our data--using intraclass correlation coefficients (ICCs) and differences between repeats and the observers. Carimas kmono values were lower than the reference--by 10.7% in the novice and by 9.6% in the expert, and were in substantial agreement with it--R(2) values were 0.944 and 0.943 correspondingly; the coefficients of repeatability--1.96 SD of biases in BA plots--were 11.2% in both the observers. The intra- and interobserver ICCs were high on global and regional levels--above 0.99 in the novice and 0.96 in the expert. The intra- and interobserver differences were low on global and regional levels, the most pronounced being the left anterior descending artery (LAD) interobserver difference of 2.2%.
  
  
  CONCLUSIONS
  The study showed extremely good reproducibility-both intra- and interobserver-for C-11 acetate PET analysis of myocardial oxidative metabolism.
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland IM Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia Faculty of Medicine, St. Petersburg State University, St. Petersburg, Russia sernes@utu.fi sergey.nesterov@tyks.fi.
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Nesterov
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Turta
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Chunlei
authors.initials: C
authors.lastname: Han
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland Department of Clinical Physiology and Nuclear Medicine, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Maija
authors.initials: M
authors.lastname: Mäki
authors.affiliation: Department of Biostatistics, University of Turku, Turku, Finland.
authors.forename: Irina
authors.initials: I
authors.lastname: Lisinen
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Helena
authors.initials: H
authors.lastname: Tuunanen
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Juhani
authors.initials: J
authors.lastname: Knuuti
mesh_terms: D000085:Acetates; D002244:Carbon; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012984:Software
chemical_list: D000085:Acetates; D019275:Radiopharmaceuticals; C438206:carbon-11 acetate; D002244:Carbon; D010100:Oxygen
keywords: C-11 acetate; Myocardial metabolism; Oxidative metabolism; Reproducibility