Greater likelihood of right-sided over left-sided carotid wall inflammation as revealed by FDG-PET/CT imaging

Objectives Aim of this study was to identify a potential side difference of left and right-sided common carotid wall inflammation (CCWI) as revealed by FDG-PET imaging.

Methods 71 patients with known or suspected cardiovascular disease underwent FDG-PET imaging to quantify CCWI in both carotids. FDG target-to-background-ratios (TBRmax) as well as TBRmax of 'most diseased segment' (MDS) of both vessels were measured and consequently classified according to different degrees of FDG uptake. Comparison of increasing cut-off values for FDG uptake values between the two carotids and univariate analyses to identify potential clinical risk factors for increasing degrees of CCWI for each carotid were performed.

Results All of the classified increasing cut-off values for FDG uptake were significantly more often found in the right carotid. Univariate analyses showed body mass index (BMI) <25 to be significantly associated with lower (TBRmax: right: p=0.003; left: p=0.008; MDS: right: p=0.002; left: p=0.007) and BMI ≥30 with higher FDG uptake values (TBRmax: right: p=0.005; left: p=0.005; MDS: right: p=0.002; left: p=0.002) in both carotids. Smoking also showed significant association with higher FDG uptake (TBRmax: right: p=0.016; left: p=0.011; MDS: right: p=0.025; left: p=0.017) also in both carotids. Contrarily, hypertension showed a significant association with increased FDG uptake values only in the right carotid (TBRmax: p=0.022; MDS: p=0.024).

Conclusions Results indicated a right-sided predilection for increasing CCWI, which might be related to hypertensive disease as the only clinical variable to be significantly associated with only right- but not left CCWI