title: Effect of perfusion pattern and imaging sequence on gated perfusion SPECT evaluation of myocardial stunning.
abstract: The aim of this study was to determine the effect of perfusion defect and imaging sequence on the evaluation of myocardial stunning with gated perfusion SPECT.
  
  
  METHODS
  A dynamic mathematic cardiac torso phantom was used to create 100 gated SPECT simulations (50 stress-rest and 50 rest-stress sequences) with a wide range of perfusion defects. No segmental wall motion abnormalities were created. After generating projection images, 2 additional acquisitions were simulated by thresholding the projected data to 25% and 75% of the maximum. Finally, gated SPECT projections were grouped by 2s to generate 2 series of phantoms corresponding to stress-rest and rest-stress imaging sequences. For each sequence, the first dataset was the 25% thresholded gated SPECT. Both 75% thresholded and 100% signal intensity were used as a second dataset. Each simulated gated SPECT image differed from others in the extent of myocardial scar or ischemia, but all had the same end-diastolic volume (EDV) (125 mL), end-systolic volume (ESV) (48 mL), and ejection fraction (EF) (62%). Left ventricular perfusion and function were each assessed using validated software.
  
  
  RESULTS
  Mean stress EDV was decreased when compared with rest-simulated data (111 +/- 4.7 and 112.4 +/- 4.8 mL, respectively; P < or = 0.05), and mean stress ESV was increased when compared with rest-simulated data (44 +/- 4.2 and 42.7 +/- 4 mL, respectively; P < 0.02). The resulting mean stress EF was decreased in the same comparison (60.3% +/- 3.1% and 62% +/- 2.7%, respectively; P = 0.0001). After multivariate analysis, the difference between stress and rest EF was significantly influenced by myocardial infarction (P = 0.0027), severe extent of myocardial ischemia (P = 0.0017), and imaging sequence (P < 0.0001). A > or =5% decrease in EF on stress SPECT (i.e., myocardial stunning) was significantly associated with the stress-rest sequence (chi(2) = 26; P < 0.0001).
  
  
  CONCLUSIONS
  Perfusion defects and imaging sequence had significant effects on the evaluation of myocardial stunning using gated perfusion SPECT.
authors.affiliation: Département de Médecine Nucléaire et Laboratoire Universitaire Quantification en Imagerie Fonctionelle, Centre Henri Becquerel, 1 rue d'Amiens, 76000 Rouen, France. alain.manrique@rouen.fnclcc.fr
authors.forename: Alain
authors.initials: A
authors.lastname: Manrique
authors.forename: Anne
authors.initials: A
authors.lastname: Hitzel
authors.forename: David
authors.initials: D
authors.lastname: Brasse
authors.forename: Pierre
authors.initials: P
authors.lastname: Véra
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D005080:Exercise Test; D015637:Gated Blood-Pool Imaging / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008955:Models, Cardiovascular; D017682:Myocardial Stunning / Q000150:complications / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology