title: Left ventricular dyssynchrony assessment by phase analysis from gated PET-FDG scans.
abstract: BACKGROUND
  The outcome of patients with severe ischaemic left ventricular (LV) dysfunction is determined by the extent of myocardial viability and the presence of LV dyssynchrony. We aimed at assessing both parameters from the same imaging method, i.e. gated positron emission tomography (PET) F18-fluorodeoxyglucose (FDG) scans.
  
  
  METHODS
  Phase analysis from Emory Cardiac Toolbox was applied on gated PET-FDG scans to assess histogram bandwidth and standard deviation (SD) as a measure of LV dyssynchrony in 30 heart failure patients (mean ejection fraction: 30.2% ± 13.8%) referred for the evaluation of myocardial viability. Cut-off values from single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) best predicting cardiac resynchronization therapy (CRT) response served as standard of reference (bandwidth < 135°; phase SD < 43°). Severe LV dyssynchrony was diagnosed if both SPECT-MPI values were above these limits. Intraclass correlation and clinical agreement in detection of severe LV dyssynchrony by PET vs SPECT were assessed.
  
  
  RESULTS
  There was a significant correlation between PET-FDG and SPECT-MPI for bandwidth (r = 0.88, P < .001) and phase SD (r = 0.88, P < .001) resulting in an excellent clinical agreement between the two methods of 93%.
  
  
  CONCLUSIONS
  Accurate LV dyssynchrony assessment by phase analysis of gated PET-FDG scans is feasible, allowing assessing myocardial viability and severe LV dyssynchrony in one scan.
authors.affiliation: Cardiac Imaging, University Hospital Zurich, Ramistrasse 100, 8091, Zurich, Switzerland.
authors.forename: Aju P
authors.initials: AP
authors.lastname: Pazhenkottil
authors.forename: Ronny R
authors.initials: RR
authors.lastname: Buechel
authors.forename: Rene
authors.initials: R
authors.lastname: Nkoulou
authors.forename: Jelena-Rima
authors.initials: JR
authors.lastname: Ghadri
authors.forename: Bernhard A
authors.initials: BA
authors.lastname: Herzog
authors.forename: Lars
authors.initials: L
authors.lastname: Husmann
authors.forename: Mathias
authors.initials: M
authors.lastname: Wolfrum
authors.forename: Silke M
authors.initials: SM
authors.lastname: Küest
authors.forename: Michael
authors.initials: M
authors.lastname: Fiechter
authors.forename: Oliver
authors.initials: O
authors.lastname: Gaemperli
authors.forename: Philipp A
authors.initials: PA
authors.lastname: Kaufmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy; D001026:Coronary Artery Bypass; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18