title: Influence of acquisition orbit on phase analysis of gated single photon emission computed tomography myocardial perfusion imaging for assessment of left ventricular mechanical dyssynchrony.
abstract: OBJECTIVE
  The association between left ventricular (LV) dyssynchrony parameters, given by phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), and acquisition orbits is unclear. The aim of this study was to assess the dependence of LV dyssynchrony parameters on acquisition orbits.
  
  
  METHODS
  Ninety-nine patients who underwent201Tl-gated SPECT MPI were categorized into minor hypoperfusion or major hypoperfusion groups. Forty-four patients who underwent99mTc-tetrofosmin-gated SPECT MPI were categorized into minor hypoperfusion or major hypoperfusion groups. The major hypoperfusion group with201Tl was divided into inferior or non-inferior wall hypoperfusion subgroups, and anteroseptal or non-anteroseptal wall hypoperfusion subgroups. Gated SPECT MPI data over a 360° acquisition orbit (360° images) and a 180° acquisition orbit (180° images) were reconstructed, and histogram bandwidth (HBW) and phase standard deviation (PSD) were compared.
  
  
  RESULTS
  Between 360° and 180° images with201Tl, there were significant differences in HBW and PSD both globally (HBW 34.8 ± 16.6 vs. 29.1 ± 10.2; PSD 8.8 ± 4.9 vs. 7.0 ± 2.3, p < 0.05 for both) and in the inferior wall (HBW 29.5 ± 15.5 vs. 23.3 ± 9.0; PSD 7.6 ± 4.6 vs. 5.6 ± 2.4, p < 0.001 for both) in the major hypoperfusion group, and also in the inferior wall in all subgroups of the major hypoperfusion group. In contrast, no segment had any significant differences in HBW or PSD between 360° and 180° images with99mTc.
  
  
  CONCLUSIONS
  Differences in acquisition orbit had a significant influence on HBW and PSD with201Tl-gated SPECT MPI in the inferior wall in patients with major hypoperfusion myocardium.
authors.affiliation: Department of Radiology, Kindai University Nara Hospital, 1248-1, Otoda-cho, Ikoma, Nara, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Misaka
authors.affiliation: Faculty of Medicine, Institute of Advanced Clinical Medicine, Kindai University, 377-2, Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan. hosono@med.kindai.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hosono
authors.affiliation: Department of Radioisotope Medicine, Atomic Bomb Disease Institute, Nagasaki University, 1-12-4, Sakamoto, Nagasaki, Nagasaki, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kudo
authors.affiliation: Department of Radiology, Kindai University Nara Hospital, 1248-1, Otoda-cho, Ikoma, Nara, Japan.
authors.forename: Takamichi
authors.initials: T
authors.lastname: Ito
authors.affiliation: Department of Radiology, Kindai University Nara Hospital, 1248-1, Otoda-cho, Ikoma, Nara, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Syomura
authors.affiliation: Department of Radiology, Kindai University Nara Hospital, 1248-1, Otoda-cho, Ikoma, Nara, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Uemura
authors.affiliation: Department of Radiology, Kindai University Nara Hospital, 1248-1, Otoda-cho, Ikoma, Nara, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Okajima
mesh_terms: D000368:Aged; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D009943:Organophosphorus Compounds / Q000737:chemistry; D015609:Organotechnetium Compounds / Q000737:chemistry; D010477:Perfusion; D019275:Radiopharmaceuticals / Q000737:chemistry; D013667:Technetium / Q000737:chemistry; D013794:Thallium Radioisotopes / Q000737:chemistry; D015899:Tomography, Emission-Computed, Single-Photon; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; C078700:technetium tc-99m tetrofosmin; D013667:Technetium
keywords: Acquisition orbit; Gated SPECT myocardial perfusion imaging; Left ventricular mechanical dyssynchrony; Phase analysis