title: An automatic alignment tool to improve repeatability of left ventricular function and dyssynchrony parameters in serial gated myocardial perfusion SPECT studies.
abstract: OBJECTIVE
  Left ventricular (LV) function and dyssynchrony parameters measured from serial gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) using blinded processing had a poorer repeatability than when manual side-by-side processing was used. The objective of this study was to validate whether an automatic alignment tool can reduce the variability of LV function and dyssynchrony parameters in serial gated SPECT MPI.
  
  
  METHODS
  Thirty patients who had undergone serial gated SPECT MPI were prospectively enrolled in this study. Thirty minutes after the first acquisition, each patient was repositioned and a gated SPECT MPI image was reacquired. The two data sets were first processed blinded from each other by the same technologist in different weeks. These processed data were then realigned by the automatic tool, and manual side-by-side processing was carried out. All processing methods used standard iterative reconstruction and Butterworth filtering. The Emory Cardiac Toolbox was used to measure the LV function and dyssynchrony parameters.
  
  
  RESULTS
  The automatic tool failed in one patient, who had a large, severe scar in the inferobasal wall. In the remaining 29 patients, the repeatability of the LV function and dyssynchrony parameters after automatic alignment was significantly improved from blinded processing and was comparable to manual side-by-side processing.
  
  
  CONCLUSIONS
  The automatic alignment tool can be an alternative method to manual side-by-side processing to improve the repeatability of LV function and dyssynchrony measurements by serial gated SPECT MPI.
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia 30322, USA.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Zhou
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Faber
authors.forename: Zenic
authors.initials: Z
authors.lastname: Patel
authors.forename: Russell D
authors.initials: RD
authors.lastname: Folks
authors.forename: Alice A
authors.initials: AA
authors.lastname: Cheung
authors.forename: Ernest V
authors.initials: EV
authors.lastname: Garcia
authors.forename: Prem
authors.initials: P
authors.lastname: Soman
authors.forename: Dianfu
authors.initials: D
authors.lastname: Li
authors.forename: Kejiang
authors.initials: K
authors.lastname: Cao
authors.forename: Ji
authors.initials: J
authors.lastname: Chen
mesh_terms: D001331:Automation; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012984:Software; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*; D016277:Ventricular Function, Left