颈动脉斑块剪切波速度与斑块内Ⅰ型／Ⅲ型胶原纤维比值的关系

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

目的应用声触诊组织成像定量技术（virtualtouchtissueimagingquantification，VTIQ）测量颈动脉斑块的剪切波速度（shearwavevelocity，SWV），并探讨swV与斑块内I型／Ⅲ型胶原纤维比值间的关系。方法选取54例颈动脉内膜剥脱术（carotidendarterectomy，CEA）的患者，术前行颈动脉斑块VTIQ检查及术后组织病理学分析。VTIQ测量各斑块的swV；术后斑块标本分别用HE染色及天狼星红一苦味酸染色。根据HE染色将54例患者分为稳定组及不稳定组。用天狼星红一苦味酸染色后的斑块在偏振光显微镜下观察，并结合Image—ProPlus5．0图像分析软件测量斑块内Ⅰ型／Ⅲ型胶原纤维比值。结果54例患者中，14例患者为稳定组，40例患者为不稳定组，两组斑块厚度及颈动脉狭窄程度比较差异均无统计学意义（P〉0．05）。稳定组斑块的SwV平均值及Ⅰ型／Ⅲ型胶原纤维比值均高于不稳定组，差异均有统计学意义（P〈0．05）。斑块swV值与斑块I型／Ⅲ型胶原纤维比值呈正相关（r=0．882，PdO．05）。根据ROC曲线可知，当斑块swV截断值为3．725m／s（曲线下面积=0．936）时来估测稳定斑块的敏感性为92．9％，特异性为80．0％，准确性为83．3％。结论颈动脉斑块剪切波速度可很好地用于反映斑块内Ⅰ型／Ⅲ型胶原纤维比值，评价斑块的稳定性。

Objective To assess the correlation between the shear wave velocity（SWV） and the ratio of type I /type I 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 type I/typel]I 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 （950//oo CI 0.818- 0.982, P 〈0.05）. The value of SWVs was closely correlated to the ratio of type Ⅰ/type Ⅲ 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 type Ⅰ/type Ⅲ collagen fiber in the plaques, and to evaluate the stability of plaque.