%0 Journal Article %A Olivier Morel %A Damien Mandry %A Emilien Micard %A Claude Kauffmann %A Zohra Lamiral %A Antoine Verger %A Elodie Chevalier-Mathias %A Julien Mathias %A Gilles Karcher %A Benoit Meneroux %A Patrick Rossignol %A Pierre-Yves Marie %T Evidence of Cyclic Changes in the Metabolism of Abdominal Aortic Aneurysms During Growth Phases: 18F-FDG PET Sequential Observational Study %D 2015 %R 10.2967/jnumed.114.146415 %J Journal of Nuclear Medicine %P 1030-1035 %V 56 %N 7 %X The rates of growth of medically treated abdominal aortic aneurysms (AAA) are difficult to determine, and relationships with parietal inflammation and with metabolic parameters from 18F-FDG PET remain unclear. This 18F-FDG PET sequential observational study was aimed at analyzing the metabolic changes accompanying the growth phases of medically treated AAA. Methods: Thirty-nine patients (37 men; age [mean ± SD], 71 ± 12 y) exhibiting small and medically treated AAA (maximal diameter, 46 ± 3 mm) underwent 18F-FDG PET and CT angiography at baseline and 9 mo later. Clinical and imaging parameter correlates of the 9-mo increase in maximal diameter were investigated; these included 18F-FDG maximal standardized uptake values (SUVmax) averaged for slices encompassing the AAA volume. Results: Of the 39 patients, 9 (23%) had a significant (≥2.5 mm) increase in maximal diameter at 9 mo, whereas the remaining 30 did not. The patients with an increase in maximal diameter at 9 mo exhibited lower SUVmax within the AAA at baseline than patients who did not have such an increase (1.80 ± 0.45 vs. 2.21 ± 0.52; P = 0.04); they also displayed a trend toward greater changes in SUVmax at 9 mo (difference between 9 mo and baseline: +0.40 ± 0.85 vs. −0.06 ± 0.57; P = 0.07). Similar levels were ultimately reached in both groups at 9 mo (2.20 ± 0.83 and 2.15 ± 0.66). SUVmax was a significant, yet modest, baseline predictor of the absolute change in maximal diameter during follow-up (P = 0.049). Conclusion: The enhancement in the maximal diameter of small AAA was preceded by a stage with a low level of 18F-FDG uptake, but this low level of uptake was no longer documented after the growth phases, suggesting a pattern of cyclic metabolic changes. %U https://jnm.snmjournals.org/content/jnumed/56/7/1030.full.pdf