![Quantification of Atherosclerotic Plaque Activity and Vascular Inflammation using [18-F] Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT)](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F3777.jpg&w=3840&q=50)
Imaging of vulnerable atherosclerotic plaques with FDG-microPET: no FDG accumulation
Jacob Marsvin Laurberg1, Aage Kristian Olsen, Søren Baarsgaard Hansen
1Department of Cardiology and Institute of Clinical Medicine, Aarhus University Hospital (Skejby), Aarhus, Denmark. jlaurberg@ki.au.dk <jlaurberg@ki.au.dk>
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).
Conclusion:
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.
Insights
Fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging did not detect advanced atherosclerosis in mouse aortas or carotids. This study questions FDG-PET
Area of Science:
- Cardiovascular Research
- Medical Imaging
- Experimental Medicine
Background:
- Non-invasive imaging methods are crucial for assessing atherosclerosis in both human patients and animal models.
- Previous studies suggested that FDG-PET could identify vulnerable, inflamed atherosclerotic plaques.
Purpose of the Study:
- To evaluate the utility of FDG-PET for detecting atherosclerosis in apoE-deficient mice.
- To determine if FDG-PET can visualize advanced atherosclerotic lesions and assess inflammation.
Main Methods:
- Atherosclerotic apoE-deficient mice underwent FDG-PET scans.
- FDG uptake was measured in various tissues, including atherosclerotic aortas, under fasting and non-fasting conditions.
- Accelerated atherosclerosis was induced via carotid ligation to assess FDG uptake in these lesions.
Main Results:
- FDG accumulation was observed but primarily attributed to interscapular brown fat, not atherosclerotic lesions.
- Aortic arch FDG uptake was paradoxically lower than in non-atherosclerotic thoracic aorta in both fasting and non-fasting states.
- Induced carotid atherosclerosis did not result in increased FDG uptake compared to non-ligated arteries.
Conclusions:
- Advanced atherosclerotic lesions in the aorta showed reduced FDG uptake, contrary to expectations.
- FDG-PET imaging failed to detect accelerated atherosclerosis in the carotid arteries.
- These findings challenge the effectiveness of FDG-PET for imaging advanced, vulnerable atherosclerotic lesions.
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