title: An assessment of the sensitivity of the Cedars-Sinai quantitative gated SPECT software to changes in the reconstruction of the short-axis slices.
abstract: OBJECTIVE
  This study assessed whether variations in count density, reconstruction filtering parameters and the short-axis orientation selected for reconstructions of myocardial short-axis slices significantly influenced the left ventricular ejection fraction (LVEF) calculated from a gated myocardial perfusion SPECT study.
  
  
  METHODS
  The Cedars-Sinai quantitative gated SPECT software package was used to estimate the LVEF from gated 99mTc-sestamibi and 201TI gated SPECT studies in 20 patients. Oblique slices were reconstructed 12 times for each study, independently varying the filter cutoff and the orientation of the short axis each time.
  
  
  RESULTS
  There were no clinically significant changes in the LVEF over the range of cutoff frequencies or orientation for either the 201TI or 99mTc-sestamibi studies. There was excellent agreement between the LVEF calculated from the 201TI and 99mTc-sestamibi studies on the same patients using the default filter (mean difference = 0.25% points).
  
  
  CONCLUSIONS
  The Cedars-Sinai quantitative gated SPECT software package for parallel-hole collimators can be used with confidence to obtain an LVEF, and is not sensitive to variations in count density, filtering parameters or short-axis orientation.
authors.affiliation: Department of Nuclear Medicine, St. George Hospital, Kogarah, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Fredericks
authors.forename: P
authors.initials: P
authors.lastname: Baxter
authors.forename: E
authors.initials: E
authors.lastname: McKay
authors.forename: R
authors.initials: R
authors.lastname: Smart
mesh_terms: D000465:Algorithms; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D012984:Software; D013318:Stroke Volume; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon; D016277:Ventricular Function, Left
chemical_list: D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D017256:Technetium Tc 99m Sestamibi