Abstract 15827: Carotid Atherosclerotic Plaques With Increased Temperature Exhibit High Fdg-Pet Uptake: Validation With Histopathological Findings
Introduction: 18F-fluorodeoxyglycose Positron Emission Tomography (FDG-PET) is regarded the gold standard for evaluation of vascular inflammation. Radiation exposure hampers its application in every day clinical practice. Previous studies have demonstrated that microwave radiometry (MWR) is a promising technique for assessing inflammatory activation in carotid arteries.
Hypothesis: There is a correlation between carotid temperature measurements derived by MWR with carotid flurodeoxyglucose (FDG) uptake and these measurements agree with findings from histology.
Methods: Consecutive patients scheduled to undergo carotid endarterectomy due to significant carotid artery stenosis were enrolled in the study. All patients underwent evaluation of both carotid arteries by FDG-PET scan and MWR. Carotid inflammation was assessed by PET/CT as target to background ratio (TBR) by obtaining measurements in consecutive axial slices 2cm below to 2cm above the carotid bifurcation. Temperature difference (ΔT) by MWR was assigned as the maximum-minimum temperature measurements over the corresponding carotid segments. Carotid endarterectomy specimens were routinely stained with hematoxylin-eosin and Von-Kossa stains. Subsequently a semi quantitative score was used to evaluate the extent of lipid core and the degree of calcification.
Results: In total 21 patients were included in the study (85.7% male). There was a significant correlation between TBR and ΔT values of all carotids, which was higher for operated carotids only (R=0.40, p=0.01 and R=0.46, p=0.03, respectively). Carotid endarterectomy specimens with high lipid core extension exhibited higher TBR and ΔT values compared to those with limited lipid core (1.71±0.37 vs. 1.42±0.32, p=0.02 and 0.62±0.17 vs. 0.44±0.08 °C, p=0.001, respectively). Conversely, specimens with extended calcification exhibited both lower FDG-PET uptake and temperature values (1.35±0.30 vs. 1.80±0.31, p<0.001 and 0.43±0.07 vs 0.65±0.16 °C).
Conclusions: There was a significant correlation between carotid temperature measurements as assessed by MWR and carotid FDG uptake as assessed by FDG-PET/CT. Measurements from both methods agreed with histological findings.
Author Disclosures: G. Benetos: None. K. Toutouzas: None. I. Koutagiar: None. A. Georgakopoulos: None. G. Agrogiannis: None. N. Bessias: None. K. Filis: None. C. Klonaris: None. G. Spyrou: None. E. Patsouris: None. C. Anagnostopoulos: None. D. Tousoulis: None.
- © 2016 by American Heart Association, Inc.