Olivier Morel1, Damien Mandry2, Emilien Micard3, Claude Kauffmann4, Zohra Lamiral5, Antoine Verger6, Elodie Chevalier-Mathias7, Julien Mathias8, Gilles Karcher6, Benoit Meneroux6, Patrick Rossignol9, Pierre-Yves Marie10. 1. Nuclear Medicine & Nancyclotep Experimental Imaging Platform, CHU Nancy, Nancy, France o.morel@chu-nancy.fr. 2. UMR 947, INSERM, Nancy, France. 3. UMR 947, INSERM, Nancy, France Faculty of Medicine, University of Lorraine, Nancy, France. 4. LCTI, Université de Montréal, Montréal, Québec, Canada. 5. Centre d'Investigation Clinique CIC-P 9501, INSERM, Nancy, France; and. 6. Nuclear Medicine & Nancyclotep Experimental Imaging Platform, CHU Nancy, Nancy, France. 7. Nuclear Medicine & Nancyclotep Experimental Imaging Platform, CHU Nancy, Nancy, France UMR 1116, INSERM, Nancy, France. 8. Department of Radiology, CHU Nancy, Nancy, France. 9. Faculty of Medicine, University of Lorraine, Nancy, France Centre d'Investigation Clinique CIC-P 9501, INSERM, Nancy, France; and UMR 1116, INSERM, Nancy, France. 10. Nuclear Medicine & Nancyclotep Experimental Imaging Platform, CHU Nancy, Nancy, France Faculty of Medicine, University of Lorraine, Nancy, France UMR 1116, INSERM, Nancy, France.
Abstract
UNLABELLED: 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 (18)F-FDG PET remain unclear. This (18)F-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 (18)F-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 (18)F-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 (18)F-FDG uptake, but this low level of uptake was no longer documented after the growth phases, suggesting a pattern of cyclic metabolic changes.
UNLABELLED: 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 (18)F-FDG PET remain unclear. This (18)F-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 (18)F-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 (18)F-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 (18)F-FDG uptake, but this low level of uptake was no longer documented after the growth phases, suggesting a pattern of cyclic metabolic changes.