In Vivo Imaging of Abdominal Aortic Aneurysms: Increased FDG Uptake Suggests Inflammation in the Aneurysm Wall

Abstract

Purpose:

To study the potential of integrated positron emission tomography and computed tomography (PET/CT) to identify aneurysm wall inflammation.

Methods:

The level of F18-fluorodeoxyglucose (FDG) uptake was studied in aneurysmal and normal-sized aortas of 34 male patients [17 with abdominal aortic aneurysm (AAA) and 17 age-matched controls] identified in a database of 278 consecutive patients evaluated for staging of primary lung cancer. The maximal standardized uptake value (SUV) was calculated to quantify FDG uptake in the AAA wall.

Results:

AAAs showed significantly higher FDG uptake than the normal-sized aorta in age-matched controls (SUV 2.52±0.52 versus 1.78±0.45, respectively; p<0.001). The level of FDG uptake did not correlate with maximal aneurysm diameter (r=0.09; 95% CI −0.42 to 0.56; p=0.7).

Conclusion:

FDG-PET/CT is a promising technique to identify inflammation of the aneurysm wall. Irrespective of aneurysm diameter, asymptomatic AAAs show more FDG uptake and more inflammatory activity in the wall than the non-dilated abdominal aorta of sex/age-matched controls. Future studies will be directed at the predictive value of increased FDG uptake for aneurysm wall strength, rupture risk, and the utility of FDG-PET/CT in assessing the effect of medical interventions.

Keywords

abdominal aortic aneurysm vascular inflammation positron emission tomography computed tomography

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