The relationship between shear wave velocity and the ratio of typeI/typeIII collagen fiber in the carotid plaques

Abstract

Objective To assess the correlation between the shear wave velocity(SWV) and the ratio of typeⅠ /typeⅢ collagen fibers in plaques using virtual touch tissue imaging quantification(VTIQ). Methods Fifty four patients (54 plaques) who scheduled to carotid endarterectomy(CEA) were enrolled in this study. Their carotid plaques were preoperatively examined using VTIQ. The value of SWE of each plaque was obtained. The SWV of the plaque was evaluated by VTIQ. The endarterectomy specimens were transferred to the pathological department immediately after surgery to evaluate the plaque types and the distribution of collagen fibers in plaques. According to HE staining, the 54 plaques were divided into stable and unstable group. Results Among 54 plaques, 14 were stable plaque and 40 were unstable plaques. The thickness and stenosis rate had no significant difference between stable group and unstable group (both P>0.05). The mean value of SWV and the ratio of typeⅠ/typeⅢ collagen fiber in stable plaques were higher than those in the unstable plaques (both P<0.05). Based on ROC analysis, a cut-off value of SWE of 3.725 m/s (AUC=0.936) showed a sensitivity of 92.9%, a specificity of 80.0% and an accuracy of 83.3% for predicting stable plaques (95% CI 0.818-0.982, P<0.05). The value of SWVs was closely correlated to the ratio of typeⅠ/typeⅢ collagen fiber in plaques(r=0.882, P<0.05). Conclusions SWV of the carotid atherosclerotic plaque can be used to reflect the ratio of the typeⅠ/typeⅢ collagen fiber in the plaques, and to evaluate the stability of plaque. Key words: Ultrasonography; Plaque, atherosclerotic; Virtual touch tissue imaging quantification; Collagen fibers