Phase analysis by gated F-18 FDG PET/CT for left ventricular dyssynchrony assessment: a comparison with gated Tc-99m sestamibi SPECT.

PURPOSE: To investigate the value of gated F-18 FDG PET/CT on left ventricular (LV) dyssynchrony assessment in comparison with gated Tc-99m sestamibi SPECT in patients with coronary artery disease (CAD).

METHODS: The data of 100 consecutive CAD patients who underwent both gated myocardial Tc-99m sestamibi SPECT and F-18 FDG PET/CT imaging were analyzed. Phase standard deviation (SD) and histogram bandwidth (BW) were derived from phase analysis using Cedars software package. The correlation and agreement of SD and BW between Tc-99m sestamibi SPECT and F-18 FDG PET/CT were examined. Myocardial viability and the site of latest activation assessed by the two imaging methods were compared as well.

RESULTS: A moderate correlation for SD (r = 0.58, p < 0.0001) and BW (r = 0.60, p < 0.0001) was found between gated SPECT and gated F-18 FDG PET/CT. Bland-Altman analysis revealed an overestimation of SD and BW (6.4° ± 14.3° and 22.0° ± 46.8°) by gated F-18 FDG PET/CT. Multivariate logistic regression analysis identified that significant LV remodeling on SPECT imaging, LV functional parameters and F-18 FDG uptake ratio of myocardium to blood pool (SUVM/B) were associated with the overestimation. Myocardial SPECT and F-18 FDG PET/CT had a 67.1 % identity in determining the latest activation site and 5.2 % more viable myocardium was detected by F-18 FDG PET/CT than SPECT.

CONCLUSION: Gated F-18 FDG PET/CT moderately correlated with gated Tc-99m sestamibi SPECT in assessing LV dyssynchrony. Gated F-18 FDG PET/CT phase analysis should be cautiously applied in CAD patients with significant LV remodeling on SPECT imaging, severe LV functional impairment or poor myocardial F-18 FDG uptake.