title: Assessment of left ventricular mechanical dyssynchrony by phase analysis of gated-SPECT myocardial perfusion imaging and tissue Doppler imaging: comparison between QGS and ECTb software packages.
abstract: BACKGROUND
  Recently, the phase analysis of gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has become feasible via several software packages for the evaluation of left ventricular mechanical dyssynchrony. We compared two quantitative software packages, quantitative gated SPECT (QGS) and Emory cardiac toolbox (ECTb), with tissue Doppler imaging (TDI) as the conventional method for the evaluation of left ventricular mechanical dyssynchrony.
  
  
  RESULTS
  Thirty-one patients with severe heart failure (ejection fraction ≤35%) and regular heart rhythm, who referred for gated-SPECT MPI, were enrolled. TDI was performed within 3 days after MPI. Dyssynchrony parameters derived from gated-SPECT MPI were analyzed by QGS and ECTb and were compared with the Yu index and septal-lateral wall delay measured by TDI. QGS and ECTb showed a good correlation for assessment of phase histogram bandwidth (PHB) and phase standard deviation (PSD) (r = 0.664 and r = 0.731, P < .001, respectively). However, the mean value of PHB and PSD by ECTb was significantly higher than that of QGS. No significant correlation was found between ECTb and QGS and the Yu index. Nevertheless, PHB, PSD, and entropy derived from QGS revealed a significant (r = 0.424, r = 0.478, r = 0.543, respectively; P < .02) correlation with septal-lateral wall delay.
  
  
  CONCLUSIONS
  Despite a good correlation between QGS and ECTb software packages, different normal cut-off values of PSD and PHB should be defined for each software package. There was only a modest correlation between phase analysis of gated-SPECT MPI and TDI data, especially in the population of heart failure patients with both narrow and wide QRS complex.
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Vali-e-Asr Ave., Niayesh Blvd., Tehran, Iran.
authors.forename: Fereydoon
authors.initials: F
authors.lastname: Rastgou
authors.forename: Maryam
authors.initials: M
authors.lastname: Shojaeifard
authors.forename: Ahmad
authors.initials: A
authors.lastname: Amin
authors.forename: Tahereh
authors.initials: T
authors.lastname: Ghaedian
authors.forename: Hasan
authors.initials: H
authors.lastname: Firoozabadi
authors.forename: Hadi
authors.initials: H
authors.lastname: Malek
authors.forename: Nahid
authors.initials: N
authors.lastname: Yaghoobi
authors.forename: Ahmad
authors.initials: A
authors.lastname: Bitarafan-Rajabi
authors.forename: Majid
authors.initials: M
authors.lastname: Haghjoo
authors.forename: Hedieh
authors.initials: H
authors.lastname: Amouzadeh
authors.forename: Hossein
authors.initials: H
authors.lastname: Barati
mesh_terms: D000465:Algorithms; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; 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*; D000091402:Prohibitins; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis*