Background Monocytes and macrophages in atherosclerotic plaque lead to plaque instability.The aim of the study was to determine if plaque neovascularization led to inflammation.Methods Patients were consecutively enrolled if their carotid intimal media thickness was ＞2 mm,as revealed by duplex ultrasound.The patients then underwent dynamic contrast enhanced magnetic resonance imaging (DCE MRI) and fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography combined with computed tomography (PET CT).A target to background ratio (TBR) of ＞1.25 or ＜1.25 served as the cutoff point for the presence and absence of inflammation,respectively.Results Twenty-six patients underwent bilateral carotid DCE MRI and 24 patients also underwent PET CT.One hundred and fifty-five plaques were evaluated by both DCE MRI and PET CT.There was no significant difference in plaque morphology between the TBR ＞1.25 (n=61) and TBR ＜1.25 (n=94) groups.No significant differences were found in plasma volume and transfer constant between the TBR ＞1.25 and TBR ＜1.25 groups.Conclusion Our study did not find a significant correlation between plaque neovascularization and the aggregation of inflammatory cells.