The Application Value Of Ultrasound Elasticity Imaging In Evaluating The Stability Of Carotid Plaques

ObjectiveDetecting carotid atherosclerotic plaques by ultrasound elasticity (UE) imaging, estimating UE images of plaques according improved elasticity scores and measuring the elastic strain ratio (B/A ratio) of plaques, then to explore the application value of the ultrasound elasticity imaging evaluating the stability of plaques.Methods1.45 patients with plaques (total of 45 plaques) were enrolled in this study. The patients who were with high hypersensitive c-reactive protein (hs-CRP) and vulnerable plaque diagnosed by two-dimensional ultrasound combining contrast-enhanced ultrasound were enrolled in the group of vulnerable plaques (total of 22 plaques). The patients who were with low hs-CRP and stable plaque diagnosed by two-dimensional ultrasound combining contrast-enhanced ultrasound were enrolled in the group of stable plaques (total of 23 plaques).2. Within 1 week after contrast-enhanced ultrasound, another ultrasound doctors, under double-blind conditions, detected plaques those were enrolled by UE imaging. Estimating UE images of plaques according improved elasticity scores and measuring the elastic strain ratio (B/A ratio) of plaques. Data were recorded.3. Data analysis:Using Kappa consistency check to evaluating the consistency of UE and joint diagnosis method in diagnosing the stability of plaques. By painting ROC curve of plaques B/A ratio to establish the optimal diagnostic critical value of plaques B/A ratio.Results1. Using improved elasticity scores:19 plaques were diagnosed vulnerable plaques by UE in the group of vulnerable plaques (total of 22 plaques), while 3 plaques were diagnosed stable plaques.17 plaques were diagnosed stable plaques by UE in the group of stable plaques (total of 23 plaques), while 6 plaques were diagnosed vulnerable plaques.2. The sensitivity, specificity and accuracy of UE diagnosis of stability of plaques were 80.00%(36/45),86.36%(19/22),73.91%(17/23); positive predictive value and negative predictive value were 13.64%,26.09%, while positive likelihood ratio and negative likelihood ratio were 3.31,0.18, respectively. Through the Kappa consistency check, Kappa value was 0.603, and we can conclude that UE and joint diagnosis method had good consistency in the diagnosis of plaque stability.3. The difference of two groups of plaque B/A ratio were statistically significant (P<0.05). The group of vulnerable plaques B/A ratio was lower than the group of stable plaques’s.4. By painting ROC curve of plaques B/A ratio, this study concluded that plaque B/A ratio of 3.92 was the best diagnostic point. When the plaque B/A ratio≥ 3.92, the plaque was likely be vulnerable plaque, while the plaque B/A ratio< 3.92 was likely be stable plaques.ConclusionDetecting plaques by UE can obtian good UE imaging of plaques. Estimating UE images of plaques according improved elasticity scores and measuring plaques B/A ratio can evaluate the stability of plaques accurately. In addition, UE is convenient and noninvasive, and it can be a reliable technology to evaluate the stability of the plaques. UE has significant clinical application value for evaluating stability of plaque.