Evaluation of carotid plaque vulnerability by contrast-enhanced ultrasound and superb microvascular imaging / 中华老年医学杂志

ABSTRACT

Objective To observe the plaque surface morphology and neo-vascularization within the plaque using superb microvascular imaging(SMI) and contrast-enhanced ultrasound(CEUS),and to compare the correlation and consistency of the two technologies based on making clinical diagnosis of symptomatic carotid artery plaque as the standard.Methods A total of 92 patients undergoing carotid ultrasonography in Beijing Tiantan Hospital from August 2016 to October 2017 were recruited,including 61 males and 31 females,aged(63.5 ± 7.7) years(range,4 2-80 years.A total of 105 plaques were found.According to whether or not to have plaque-induced ipsilateral ischemic symptoms,patients were divided double-blindly into the symptom group and the non-symptom group.The features of plaque (including surface morphology and neo-vascularization) were recorded.The ultrasonographic findings were chi-squarely tested.Results There were statistically significant differences in the surface morphology and enhancement degree of CEUS between carotid artery plaque-induced ischemic symptom group and the non-symptom group(x2 =6.865,P =0.032;x2 =22.494,P ＜ 0.001).The SMI-detected surface morphology and neo-vascularization had statistically significant differences between the two groups (x2 =10.367,P =0.006;x2 =8.186,P =0.041).The correlations of plaque surface morphology(r =0.856,P ＜ 0.001)and diagnostic consistency(r=0.802,P＜0.001)between SMI and CEUS were higher.In the symptom group,SMI-showed plaque fissures and small surface pitting were in 33.9 ％ (20/59) of patients,and CEUS-showed plaque fissures and small surface pitting were in 25.4％ (15/59)of patients.And SMI had a better detection rate of slight and irregular appearances on plaque surface.Taking the first grade of the plaque surface as the standard,CEUS showed a sensitivity of 42.4％ and specificity of 80.4％ for detecting symptomatic plaques,and SMI showed a sensitivity of 54.2 ％ and specificity of 76.1％.The two methods had similar specificity,and SMIhad a slightly higher sensitivity than did CEUS.CEUS and SMI had a good correlation of plaque neo-vascularization(r =0.802,P ＜ 0.001)and a moderate diagnostic consistency(r=0.539,P ＜0.001).Taking the enhancement level of 2 as the standard,CEUS showed a sensitivity of 75.8 ％ and specificity of 67.4 ％ for detecting the symptomatic plaque,and SMI showed a sensitivity of 58.6％ and specificity of 69.5％.The two methods had similar specificity,and CEUS had a higher sensitivity than did SMI.Conclusions SMI and CEUS have a good consistency for detecting plaque surface morphology.SMI and CEUS are more correlated with plaque-induced symptoms than is two-dimensional ultrasound.The SMI has a higher display rate and repeatability than does CEUS for detecting the small fissures and the surface features of plaques.Compared with SMI-detected neo-vascularization,the degree of CEUS enhancement is more correlated with the symptoms.The specificity of CEUS and SMI is similar,and the sensitivity of CEUS is higher than that of SMI.