High Levels of 18F-FDG Uptake in Aortic Aneurysm Wall are Associated with High Wall Stress

A. PET-CT fusion image of the TAA in patient 1 (a) showing positive 18-FDG uptake in the terminal aorta, and the corresponding wall stress contours (b). The location of peak wall stress is indicated with a black triangle. B. Transverse images of fused PET-CT in the terminal thoracic aorta of patient 1 at initial examination (a), predicted wall stress contours at the same location (b), and contrast-enhanced CT acquired 6 months later (c) showing a markedly larger and ruptured descending aorta, associated with left pleural effusion (white asterisk).

A. CT image of the inflammatory AAA in patient 4 (a), transverse images of fused PET-CT (b) showing positive 18-FDG update in the aneurysm neck, and the predicted wall stress (c). B. Top view of the predicted wall stress in the AAA of patient 4 (a) and the corresponding PET image (b) showing good correspondence between locations of high wall stress and positive 18-FDG uptake.

PET-CT images of the AAA in patient 5 (a) and (d) acquired at initial examination, and contrast-enhanced CT images acquired 6 months later showing early stage of rupture (white arrow) at the junction between the neck and AAA sac on the posterior wall (b), and at a distal section (c) showing peritoneal haematoma (white arrow). Predicted wall stress based on initial CT images is shown in (e) for a transverse section corresponding to the same location as (a), and predicted wall shear stress contours (f).