Leon Jonathan Menezes BMBCH, Presenter: Nothing to Disclose

Ashley McAllister Groves MBBS, Abstract Co-Author: Nothing to Disclose

Irfan Akbar Kayani MBBS, Abstract Co-Author: Nothing to Disclose

Sue Siew Chen Chua MBBS, Abstract Co-Author: Nothing to Disclose

Simona Ben Haim MD, Abstract Co-Author: Nothing to Disclose

Brian Hutton, Abstract Co-Author: Nothing to Disclose

Jamshed Bomanji MBBS, Abstract Co-Author: Nothing to Disclose

Peter Josef Ell MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

It is hypothesized that arterial plaque 18F-FDG avidity on PET imaging predicts atheromatous instability, possibly reflecting inflammation induced by macrophage recruitment and/or proliferation at affected sites. We performed serial 18F-FDG vascular measurements in an attempt to evaluate the natural history of avid arterial plaques on PET.

We retrospectively examined PET/CT images from all the oncology patients presenting to our Institution in the last 3 years that had had a minimum of 4 examinations. This represented 126 PET/CT studies in total, from 21 patients (11 women, 10 men, 18-70 years old, mean age at presentation 40.8, average of 6 scans per patient). The average length of follow-up was 29.6 months. Images of the carotids and the aorta were evaluated visually for areas of calcification and for focal areas of increased 18F-FDG activity with a Standardized Uptake Value (SUV) >2.5. The CT number of the vessel wall at this site was also recorded. By examining the appearances of these vascular 18F-FDG avid sites on prior and subsequent studies a plot of SUV and Hounsfield units was made versus time.

In the 126 studies, the initial prevalence of increased vessel wall 18F-FDG uptake was 38% (8/21). The initial prevalence of arterial calcification was 33% (7/21). The number of patients who developed new FDG uptake was 16/21. The number who developed new arterial calcification was 14/21. 73 sites of 18F-FDG uptake in total were observed longitudinally. Focal 18F-FDG avid vascular uptake did not persist and SUV values at such sites progressively fell with time. There was no correlation between 18F-FDG uptake and the CT number of the vessel wall. No calcifications developed in the sites of focal 18F-FDG avid lesions during the follow up period.

The findings in this study yield insight into the natural history of focal 18F-FDG avid arterial lesions. Such lesions appear to represent a transient phenomenon.

18F-FDG PET/CT may have an important role in imaging vulnerable atherosclerotic plaques and could have potential for monitoring therapeutic interventions.

Menezes, L, Groves, A, Kayani, I, Chua, S, Ben Haim, S, Hutton, B, Bomanji, J, Ell, P, et al, , What Is the Natural History of Focal Increased 18F-FDG Uptake In Arterial Atheroma on PET/CT Imaging? A Retrospective Longitudinal Study.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4427195.html