title: Dependence of left ventricular functional parameters on image acquisition time in cardiac-gated myocardial perfusion SPECT.
abstract: BACKGROUND
  Reduction of image acquisition time in single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) examinations has been considered. However, association between left ventricular (LV) functional parameters and acquisition time is unclear.
  
  
  METHODS
  Twenty-four patients referred to one-day stress/rest SPECT MPI examinations were imaged at rest with dual-headed gamma camera. List-mode emission data were processed into sets of cardiac-gated images corresponding to different acquisition times: 20%, 30%, 40%, 50%, 60%, 80%, and 100% of total acquisition time (30 seconds per projection). Image quality was quantitatively evaluated by computing contrast-to-noise ratio. LV volumes, wall motion, wall thickening, and mechanical dyssynchrony were quantified with automatic clinical software (QGS; Cedars-Sinai Medical Center).
  
  
  RESULTS
  A significant negative dependence was found between phase analysis parameter values and image acquisition time. Differences in LV volume parameters were small but statistically significant at relative acquisition times of less than 50%. LV wall motion and wall thickening were found to be robust to the increase of noise.
  
  
  CONCLUSIONS
  Image acquisition time of gated SPECT MPI examination can be reduced to 15 seconds per projection without significantly affecting LV volumes, wall motion, or wall thickening. However, reduction of acquisition time has a significant effect on phase analysis results.
authors.affiliation: Diagnostic Imaging Centre, Kuopio University Hospital, POB 100, 70029 KYS, Kuopio, Finland, matti.kortelainen@kuh.fi.
authors.forename: Matti J
authors.initials: MJ
authors.lastname: Kortelainen
authors.forename: Tuomas M
authors.initials: TM
authors.lastname: Koivumäki
authors.forename: Marko J
authors.initials: MJ
authors.lastname: Vauhkonen
authors.forename: Mikko A
authors.initials: MA
authors.lastname: Hakulinen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*