Relation between Carotid Stenosis Severity, Plaque Echogenicity Characteristics and IMT Assessed by Ultrasound in the Community Population of Southern China

Carotid artery atherosclerosis (CAA) is one of the major high-risk mechanisms of stroke. Relationship between IMT, carotid plaque echogenicity and carotid stenosis assessed by ultrasound has not been systemically studied, especially in subjects with mild to moderate carotid stenosis. In this study we measured these 3 different ultrasound-derived quantitative traits concurrently in the community population of southern China and compared their associations. We found that IMT_mean in the non-stenosis group (0%), <30% group and ≥30% group were 0.72 ± 0.11 mm, 0.85 ± 0.13 mm, 0.90 ± 0.17 mm respectively. IMT_mean of the <30% group and ≥30% group were higher than that of 0% group (P < 0.01), ≥30% group was higher than <30% group (P < 0.01). IMT_mean in the no-plaque group, hyperechoic group and hypoechoic group were 0.75 ± 0.13 mm, 0.87 ± 0.17 mm, 0.84 ± 0.15 mm respectively. IMT_mean of the hyperechoic group and the hypoechoic group was higher than that of the no-plaque group (P < 0.01), IMT_mean of the hypoechoic group was lower than that of the hyperechoic group, though with no statistic significance (P = 0.58). The proportion of hyperechoic or hypoechoic plaque in the <30% group was higher than that in the non-stenosis group (P < 0.01), as well as proportion of hypoechoic plaque in the ≥30% group was higher than that in the <30% group (P < 0.01). Our study indicated that there is definite correlation between stenosis severity, plaque echogenicity characteristics and IMT in evaluation the extent of CAA with ultrasound. The result suggests that the 3 different ultrasound-derived quantitative traits, are a progressing process, and this process increases the risk of stroke, thus medical treatment especially stabilizing the plaques is necessary.