title: The suitability of gamma camera coincidence systems for nitrogen 13-labeled ammonia myocardial perfusion imaging: a quantitative comparison with full-ring PET.
abstract: BACKGROUND
  The aim of this study was to examine the quality of nitrogen 13-labeled ammonia (NH(3)) perfusion data from coincidence-capable gamma camera positron emission tomography (GC-PET) systems compared with that from full-ring positron emission tomography (FR-PET).
  
  
  RESULTS
  The performance parameters of the GC-PET system were examined and found adequate for imaging at the activity levels used clinically. We studied 15 patients who underwent stress and rest N-13-labeled NH(3) perfusion imaging on FR-PET and GC-PET systems. Quantitative analysis of perfusion values showed that GC-PET uptake was significantly lower than FR-PET uptake in 67.6% of segments. Bland-Altman analysis showed that the mean difference between FR-PET and GC-PET values was from 5.3% to 5.9%. Stress FR-PET identified 49 segments as having impaired perfusion, 46 (93.9%) of which were also identified by GC-PET. Fifty-six additional segments were identified as abnormal by GC-PET. These findings indicated a general overestimation of defect size on GC-PET. Analysis of the degree of perfusion reduction also found that GC-PET tended to overestimate defect contrast. These findings are similar to those previously found by workers examining fluorine 18-fluorodeoxyglucose uptake by both techniques.
  
  
  CONCLUSIONS
  Good concordance was shown between GC-PET and FR-PET systems for N-13-labeled NH(3) perfusion imaging, although further work is required to optimize the technique.
authors.affiliation: Department of Bio-medical Physics and Bio-engineering, University of Aberdeen, Grampian University Hospitals NHS Trust, Foresterhill, United Kongdom. f.mckiddie@biomed.abdn.ac.uk
authors.forename: Fergus I
authors.initials: FI
authors.lastname: McKiddie
authors.forename: Howard G
authors.initials: HG
authors.lastname: Gemmell
authors.forename: E Joyce
authors.initials: EJ
authors.lastname: Davidson
authors.forename: Andrew
authors.initials: A
authors.lastname: Welch
authors.forename: Mohaned
authors.initials: M
authors.lastname: Egred
mesh_terms: D000368:Aged; D000641:Ammonia; D009202:Cardiomyopathies / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging*; D019544:Equipment Failure Analysis; D005260:Female; D015902:Gamma Cameras; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009590:Nitrogen Radioisotopes; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed / Q000295:instrumentation* / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000209:etiology
chemical_list: D009590:Nitrogen Radioisotopes; D019275:Radiopharmaceuticals; D000641:Ammonia