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, 42-80 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(χ2=6.865, P=0.032; χ2=22.494, P<0.001). The SMI-detected surface morphology and neo-vascularization had statistically significant differences between the two groups(χ2=10.367, P=0.006; χ2=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 SMI had 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.