Imaging of vulnerable atherosclerotic plaques with FDG-microPET: no FDG accumulation.
BACKGROUND
Non-invasive methods of evaluating atherosclerosis in humans and experimental animals are needed. Studies indicate that FDG-PET has a potential to detect vulnerable, inflamed atherosclerotic lesions.


METHODS
Nine atherosclerotic apoE-deficient mice were PET scanned. Four to determine optimal timing for imaging, and five post mortem after 1h redistribution of FDG and again after sequential removal of the interscapular brown fat and the atherosclerotic aortic arch. Uptake in various tissues in fasting (n=13) and non-fasting (n=7) apoE-deficient mice, including atherosclerotic and non-atherosclerotic aorta, was measured. Finally, accelerated atherosclerosis was induced by carotid ligation (n=12), and FDG-uptake was measured.


RESULTS
FDG accumulation initially thought to correspond to the atherosclerotic aortic arch was recorded. Removal of interscapular brown fat, but not atherosclerotic aortic arch, removed the signal. The aortic arch accumulated less FDG than the non-atherosclerotic thoracic aorta both in fasting (ratio 0.5, p=0.008) and non-fasting (ratio 0.33, p=0.02) conditions. Carotid atherosclerosis likewise failed to increase FDG-uptake compared to the non-ligated artery (ratio 1.03).


CONCLUSIONS
Spontaneously developed advanced atherosclerotic lesions in aorta were, paradoxically, associated with reduced FDG uptake, and accelerated carotid atherosclerosis also failed to increase FDG-uptake. The results seriously question the potential of FDG-PET for imagining of advanced, vulnerable atherosclerotic lesions.
Laurberg
Jacob Marsvin
JM
Department of Cardiology and Institute of Clinical Medicine, Aarhus University Hospital (Skejby), Aarhus, Denmark. jlaurberg@ki.au.dk <jlaurberg@ki.au.dk>
Olsen
Aage Kristian
AK
Hansen
Søren Baarsgaard
SB
Bottcher
Morten
M
Morrison
Matthew
M
Ricketts
Sally-Ann
SA
Falk
Erling
E
D002001:Adipose Tissue, Brown / Q000000981:diagnostic imaging / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000000981:diagnostic imaging* / Q000378:metabolism; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000378:metabolism; D001057:Apolipoproteins E / Q000172:deficiency; D001161:Arteriosclerosis / Q000000981:diagnostic imaging*; D005215:Fasting; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D051379:Mice; D049268:Positron-Emission Tomography
D001057:Apolipoproteins E; D019788:Fluorodeoxyglucose F18