title: Evidence of Cyclic Changes in the Metabolism of Abdominal Aortic Aneurysms During Growth Phases: ¹⁸F-FDG PET Sequential Observational Study.
abstract: 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).
  
  
  CONCLUSIONS
  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.
authors: Nuclear Medicine & Nancyclotep Experimental Imaging Platform, CHU Nancy, Nancy, France o.morel@chu-nancy.fr.
authors: Olivier
authors: O
authors: Morel
authors: UMR 947, INSERM, Nancy, France.
authors: Damien
authors: D
authors: Mandry
authors: UMR 947, INSERM, Nancy, France Faculty of Medicine, University of Lorraine, Nancy, France.
authors: Emilien
authors: E
authors: Micard
authors: LCTI, Université de Montréal, Montréal, Québec, Canada.
authors: Claude
authors: C
authors: Kauffmann
authors: Centre d'Investigation Clinique CIC-P 9501, INSERM, Nancy, France; and.
authors: Zohra
authors: Z
authors: Lamiral
authors: Nuclear Medicine & Nancyclotep Experimental Imaging Platform, CHU Nancy, Nancy, France.
authors: Antoine
authors: A
authors: Verger
authors: Nuclear Medicine & Nancyclotep Experimental Imaging Platform, CHU Nancy, Nancy, France UMR 1116, INSERM, Nancy, France.
authors: Elodie
authors: E
authors: Chevalier-Mathias
authors: Department of Radiology, CHU Nancy, Nancy, France.
authors: Julien
authors: J
authors: Mathias
authors: Nuclear Medicine & Nancyclotep Experimental Imaging Platform, CHU Nancy, Nancy, France.
authors: Gilles
authors: G
authors: Karcher
authors: Nuclear Medicine & Nancyclotep Experimental Imaging Platform, CHU Nancy, Nancy, France.
authors: Benoit
authors: B
authors: Meneroux
authors: Faculty of Medicine, University of Lorraine, Nancy, France Centre d'Investigation Clinique CIC-P 9501, INSERM, Nancy, France; and UMR 1116, INSERM, Nancy, France.
authors: Patrick
authors: P
authors: Rossignol
authors: Nuclear Medicine & Nancyclotep Experimental Imaging Platform, CHU Nancy, Nancy, France Faculty of Medicine, University of Lorraine, Nancy, France UMR 1116, INSERM, Nancy, France.
authors: Pierre-Yves
authors: PY
authors: Marie
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D050197:Atherosclerosis / Q000503:physiopathology; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D019275:Radiopharmaceuticals / Q000737:chemistry*; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 18F-FDG; CT angiography; PET; abdominal aortic aneurysms; maximal diameter