title: Comparison of attenuation, dual-energy-window, and model-based scatter correction of low-count SPECT to 82Rb PET/CT quantified myocardial perfusion scores.
abstract: BACKGROUND
  New reconstruction algorithms allow reduction in acquisition times or the amount of injected radioactivity. We examined the impact of different corrections on low-count clinical SPECT myocardial perfusion images (MPI) and compared to (82)Rb PET/CT. We compared no corrections (NC) to attenuation correction (AC) with and without scatter correction by either a dual-energy-window (AC-DEW) or model-based (AC-ESSE) approach. All reconstructions included resolution recovery.
  
  
  METHODS
  56 patients were imaged using a standard rest/stress Tc-99m-tetrofosmin MPI SPECT/CT protocol with an additional half-time acquisition. A (82)Rb-rest/stress PET/CT MPI was acquired within 4 weeks. Reconstruction methods were compared using summed rest/stress/difference scores from an objective algorithm (SRS/SSS/SDS).
  
  
  RESULTS
  The SRS and SSS for NC were significantly (P < .01) higher than for AC, but well correlated (r ≥ 0.87). The correlation in SRS/SSS among AC, AC-DEW, and AC-ESSE was excellent (r ≥ 0.98). AC-ESSE and AC-DEW had higher SRS (P ≤ .05) than AC, but the SDS values were not significantly different. Concordance with PET normal/abnormal classification was 76% for NC and ≥85% for the AC methods.
  
  
  CONCLUSIONS
  AC significantly improves the accuracy of low-count myocardial perfusion SPECT half-time imaging for the detection of disease compared to NC. Compared to PET, there was no significant difference among AC, AC-DEW, and AC-ESSE.
authors.affiliation: Department of Medicine, University of Ottawa, Ottawa, ON, Canada, gwells@ottawaheart.ca.
authors.forename: R Glenn
authors.initials: RG
authors.lastname: Wells
authors.forename: Karen
authors.initials: K
authors.lastname: Soueidan
authors.forename: Rachel
authors.initials: R
authors.lastname: Timmins
authors.forename: Terrence D
authors.initials: TD
authors.lastname: Ruddy
mesh_terms: D000368:Aged; D000465:Algorithms; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005080:Exercise Test; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D055414:Myocardial Perfusion Imaging; D015588:Observer Variation; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012414:Rubidium Radioisotopes; D012542:Scattering, Radiation; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D012414:Rubidium Radioisotopes; D017256:Technetium Tc 99m Sestamibi