title: Optimal reproducibility of gated sestamibi and thallium myocardial perfusion study left ventricular ejection fractions obtained on a solid-state CZT cardiac camera requires operator input.
abstract: OBJECTIVE
  To evaluate the reproducibility of serial re-acquisitions of gated Tl-201 and Tc-99m sestamibi left ventricular ejection fraction (LVEF) measurements obtained on a new generation solid-state cardiac camera system during myocardial perfusion imaging and the importance of manual operator optimization of left ventricular wall tracking.
  
  
  METHODS
  Resting blinded automated (auto) and manual operator optimized (opt) LVEF measurements were measured using ECT toolbox (ECT) and Cedars-Sinai QGS software in two separate cohorts of 55 Tc-99m sestamibi (MIBI) and 50 thallium (Tl-201) myocardial perfusion studies (MPS) acquired in both supine and prone positions on a cadmium zinc telluride (CZT) solid-state camera system. Resting supine and prone automated LVEF measurements were similarly obtained in a further separate cohort of 52 gated cardiac blood pool scans (GCBPS) for validation of methodology and comparison. Appropriate use of Bland-Altman, chi-squared and Levene's equality of variance tests was used to analyse the resultant data comparisons.
  
  
  RESULTS
  For all radiotracer and software combinations, manual checking and optimization of valve planes (+/- centre radius with ECT software) resulted in significant improvement in MPS LVEF reproducibility that approached that of planar GCBPS. No difference was demonstrated between optimized MIBI/Tl-201 QGS and planar GCBPS LVEF reproducibility (P = .17 and P = .48, respectively). ECT required significantly more manual optimization compared to QGS software in both supine and prone positions independent of radiotracer used (P < .02).
  
  
  CONCLUSIONS
  Reproducibility of gated sestamibi and Tl-201 LVEF measurements obtained during myocardial perfusion imaging with ECT toolbox or QGS software packages using a new generation solid-state cardiac camera with improved image quality approaches that of planar GCBPS however requires visual quality control and operator optimization of left ventricular wall tracking for best results. Using this superior cardiac technology, Tl-201 reproducibility also appears at least equivalent to sestamibi for measuring LVEF.
authors.affiliation: Department of Nuclear Medicine, Alfred Hospital, Monash University, Commercial Road, Melbourne, VIC 3004, Australia. m.cherk@alfred.org.au
authors.forename: Martin H
authors.initials: MH
authors.lastname: Cherk
authors.forename: Jason
authors.initials: J
authors.lastname: Ky
authors.forename: Kenneth S K
authors.initials: KS
authors.lastname: Yap
authors.forename: Patrina
authors.initials: P
authors.lastname: Campbell
authors.forename: Catherine
authors.initials: C
authors.lastname: McGrath
authors.forename: Michael
authors.initials: M
authors.lastname: Bailey
authors.forename: Victor
authors.initials: V
authors.lastname: Kalff
mesh_terms: D001331:Automation; D002104:Cadmium / Q000737:chemistry; D002309:Cardiology / Q000379:methods; D015637:Gated Blood-Pool Imaging / Q000379:methods; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012984:Software; D013318:Stroke Volume; D017256:Technetium Tc 99m Sestamibi; D013691:Tellurium / Q000737:chemistry; D013793:Thallium; D014584:User-Computer Interface; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging; D016277:Ventricular Function, Left / Q000502:physiology*; D015032:Zinc / Q000737:chemistry
chemical_list: C474490:CdZnTe; D019275:Radiopharmaceuticals; D002104:Cadmium; D017256:Technetium Tc 99m Sestamibi; D013793:Thallium; D015032:Zinc; D013691:Tellurium