RT Journal Article SR Electronic T1 Vascular Inflammation Imaging with 18F-FDG PET/CT: When to Image? JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 854 OP 857 DO 10.2967/jnumed.108.061432 VO 50 IS 6 A1 Leon J. Menezes A1 Carl W. Kotze A1 Brian F. Hutton A1 Raymondo Endozo A1 John C. Dickson A1 Ian Cullum A1 Syed W. Yusuf A1 Peter J. Ell A1 Ashley M. Groves YR 2009 UL http://jnm.snmjournals.org/content/50/6/854.abstract AB We prospectively investigated the ideal imaging time to measure vascular uptake after injection of 18F-FDG. Methods: A total of 17 patients with atherosclerotic abdominal aortic aneurysm underwent dynamic abdominal PET/CT using 2-min frames between 45 and 53, 57 and 65, 115 and 123, and 175 and 183 min after injection of 18F-FDG. For each period of dynamic imaging, vessel wall and lumen uptake were measured using the maximum standardized uptake value (SUVmax) and target-to-background ratio (TBR). Results: No significant difference in TBR across all time points (repeated measures ANOVA, P = 0.206) was observed, despite a significant difference in aortic wall and lumen uptake with time (repeated measures ANOVA, P = 0.02 and P < 0.001, respectively). There was no significant difference between aortic wall uptake at 60 min (SUVmax, 2.15 ± 0.11 SE) and 180 min (SUVmax, 1.99 ± 0.18 SE) (paired t test, P = 0.367). There was a significant difference in lumen uptake at 60 min (SUVmax, 2.4 ± 0.11 SE) and 180 min (SUVmax, 1.7 ± 0.1 SE) (paired t test, P = 0.001). There was no significant difference in TBR between 60 min (0.91 ± 0.03) and 180 min (1.01 ± 0.06 SE) (paired t test, P = 0.131). With increasing delayed imaging, there was increasing variability (SE) in the SUVmax for the aortic wall and TBRs. Conclusion: There was no significant advantage in imaging at 3 h over 1 h after 18F-FDG injection.