Abstract 12939: 18F-Sodium Fluoride Positron Emission Tomography for Molecular Imaging of Coronary Atherosclerosis Based on Computed Tomography Analysis

Background: Arterial 18 F-sodium fluoride ( 18 F-NaF) uptake on positron emission tomography (PET) has been reported to reflect active atherosclerosis with osteogenesis and inflammatory stimulus. We evaluated the relation of 18 F-NaF uptake to computed tomography (CT)-based coronary atherosclerosis. Methods: We enrolled 25 patients with ≥1 coronary atherosclerotic lesions detected on cardiac CT, who underwent 18 F-NaF PET/CT. Each lesion was evaluated with luminal stenosis and plaque types (calcium plaque = CP, non-calcified plaque = NCP, and partially calcified plaque = PCP) on coronary CT angiography. For CP and PCP, focal calcium density and volume were measured on plain CT images. For NCP and PCP, the presence of CT-based high-risk features (minimum CT density ≤30 Hounsfield units, and vascular remodeling index ≥1.1) was determined. Focal 18 F-NaF uptake of each lesion on PET/CT was quantified by maximum tissue-to-background ratio (TBR max ). Results: A total of 87 lesions were studied. In a patient-based analysis, 12 patients having a past history of myocardial infarction or unstable angina showed higher maximum TBR max per patient than those without (Fig 1). In a lesion-based analysis, PCP had higher TBR max than CP and NCP, and the lesions with high-risk features had higher TBR max than those without (Fig 2, 3), while TBR max did not correlate with focal calcium density (r = 0.05, p = 0.65) or volume (r = 0.18, p = 0.12). On multivariate analysis adjusted for the presence of >50% stenosis, focal calcium density and volume, and location of lesions, the plaque type of PCP showed a significant correlation with increased TBR max (β = 0.57, p Conclusions: Coronary arterial 18 F-NaF uptake, independently of calcium amount, is related to the heterogeneous and high-risk features of coronary atherosclerosis based on CT analysis. 18 F-NaF PET/CT may provide a new molecular imaging approach to identify high-risk patients and coronary lesions, in combination with cardiac CT.