Relation between carotid vulnerable plaques and peripheral leukocyte: a case-control study of comparison utilizing multi-parametric contrast-enhanced ultrasound

Background This study evaluates carotid vulnerable plaques using contrast-enhanced ultrasound (CEUS) and explores the relationship between vulnerable plaques and leukocytes. Methods Sixty-two symptomatic and 54 asymptomatic patients underwent CEUS. The images were analyzed using time-intensity and fitting curves, and peak (P-TIC), mean (M-TIC), peak (P-FC), sharpness (S-FC), and area under the curve (AUC(FC)) were obtained. The relations between CEUS parameters and leukocytes were analyzed. Results In the symptomatic group, total leukocytes and neutrophils were higher, while lymphocyte was decreased; P-TIC, M-TIC, P-FC, S-FC, and AUC(FC) were significantly higher; M-TIC and AUC(FC) were negatively correlated with lymphocytes, and M-TIC was positively correlated with neutrophils. Classification and regression tree analysis showed that M-TIC at a cutoff of 20.8 and AUC(FC) at a cutoff of 8.8 resulted in a predictive of acute cerebral infarction, accuracy of 84.3%, sensitivity of 87.1%, and specificity of 81.5%. Conclusions The variation in the perivascular leucocyte is significantly related to intraplaque inflammatory activities, CEUS is a feasible monitor of intraplaque neovascularization, so CEUS combined with perivascular leucocyte could be helpful as a warning for vulnerable plaques.