title: Simultaneous cardiac output and regional myocardial perfusion determination with PET and nitrogen 13 ammonia.
abstract: BACKGROUND
  The purpose of this study was to evaluate the possibility of measuring cardiac output during positron emission tomography (PET) examination of myocardial perfusion with nitrogen 13 ammonia.
  
  
  RESULTS
  In 7 patients undergoing right-sided cardiac catheterization for evaluation of heart failure and 6 patients who had undergone heart transplantation, a thermodilution catheter for continuous measurement of cardiac output was inserted. An N-13 ammonia scan of the heart was subsequently performed, and with use of factor analysis, the time-activity curve from the right ventricle was derived from the dynamic image sequence. The PET-derived cardiac output was subsequently obtained according to the Stewart-Hamilton principle as the amount of injected tracer divided by the area under the time-activity curve. PET-acquired cardiac output measurements correlated closely with the invasively determined values for a wide range of cardiac output values (P < .0001). The mean difference was 0.12 L/min, with an SD of 0.74 L/min. The interobserver variation was low, with a mean difference of 0.06 L/min and an SD of 0.46 L/min.
  
  
  CONCLUSIONS
  Cardiac output determination with N-13 ammonia and PET appears to be both accurate and precise and can be performed simultaneously with measurement of myocardial perfusion.
authors.affiliation: Cardiovascular PET Research Unit, Department of Cardiology, The Heart Center, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark. jhove@dadlnet.dk
authors.forename: Jens D
authors.initials: JD
authors.lastname: Hove
authors.forename: Klaus F
authors.initials: KF
authors.lastname: Kofoed
authors.forename: Hsiao M
authors.initials: HM
authors.lastname: Wu
authors.forename: Søren
authors.initials: S
authors.lastname: Holm
authors.forename: Lars
authors.initials: L
authors.lastname: Friberg
authors.forename: Christian
authors.initials: C
authors.lastname: Meyer
authors.forename: Jan
authors.initials: J
authors.lastname: Aldershvile
authors.forename: Birger
authors.initials: B
authors.lastname: Hesse
authors.forename: Henning
authors.initials: H
authors.lastname: Kelbaek
mesh_terms: D000328:Adult; D000368:Aged; D000641:Ammonia; D006328:Cardiac Catheterization; D002302:Cardiac Output / Q000502:physiology*; D003326:Coronary Circulation / Q000502:physiology*; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D016027:Heart Transplantation; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009590:Nitrogen Radioisotopes; D015588:Observer Variation; D015203:Reproducibility of Results; D013815:Thermodilution / Q000379:methods; D014055:Tomography, Emission-Computed
chemical_list: D009590:Nitrogen Radioisotopes; D000641:Ammonia