This study evaluates the performance of an acoustic radiation force impulse (ARFI)-based outcome parameter, the decadic logarithm of the variance of acceleration, or log(VoA), for measuring carotid fibrous cap thickness. Carotid plaque fibrous cap thickness measurement by log(VoA) was compared to that by ARFI peak displacement (PD) in patients undergoing clinically indicated carotid endarterectomy using a spatially-matched histological validation standard. Fibrous caps in parametric log(VoA) and PD images were automatically segmented using a custom clustering algorithm, and a pathologist with expertise in atherosclerosis hand-delineated fibrous caps in histology. Over 10 fibrous caps, log(VoA)-derived thickness was more strongly correlated to histological thickness than PD-derived thickness, with Pearson correlation values of 0.98 for log(VoA) compared to 0.89 for PD. The log(VoA)-derived cap thickness also had better agreement with histology-measured thickness, as assessed by the concordance correlation coefficient (0.95 versus 0.62), and, by Bland-Altman analysis, was more consistent than PD-derived fibrous cap thickness. These results suggest that ARFI log(VoA) enables improved discrimination of fibrous cap thickness relative to ARFI PD and further contributes to the growing body of evidence demonstrating ARFI’s overall relevance to delineating the structure and composition of carotid atherosclerotic plaque for stroke risk prediction.

中文翻译：

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通过 ARFI 加速度方差测量颈动脉斑块纤维帽厚度：体内人类结果。

本研究评估基于声辐射力脉冲 (ARFI) 的结果参数、加速度方差的十进制对数或 log(VoA) 的性能，用于测量颈动脉纤维帽厚度。使用空间匹配的组织学验证标准，在接受有临床指征的颈动脉内膜切除术的患者中，通过 log(VoA) 测量颈动脉斑块纤维帽厚度与 ARFI 峰值位移 (PD) 进行比较。参数 log (VoA) 和 PD 图像中的纤维帽使用自定义聚类算法自动分割，并且具有动脉粥样硬化专业知识的病理学家在组织学中手工描绘了纤维帽。超过 10 个纤维帽，log(VoA) 衍生的厚度与组织学厚度​​的相关性比 PD 衍生的厚度更强烈，Pearson 相关值为 0。log(VoA) 为 98，而 PD 为 0.89。log(VoA) 衍生的帽厚度也与组织学测量的厚度具有更好的一致性，如通过一致性相关系数评估（0.95 对 0.62），并且，通过 Bland-Altman 分析，比 PD 衍生的纤维帽厚度更一致. 这些结果表明，ARFI log(VoA) 能够改善相对于 ARFI PD 的纤维帽厚度的区分，并进一步有助于越来越多的证据证明 ARFI 与描绘颈动脉粥样硬化斑块的结构和组成以预测中风风险的总体相关性。比 PD 衍生的纤维帽厚度更一致。这些结果表明，ARFI log(VoA) 能够改善相对于 ARFI PD 的纤维帽厚度的区分，并进一步有助于越来越多的证据证明 ARFI 与描绘颈动脉粥样硬化斑块的结构和组成以预测中风风险的总体相关性。比 PD 衍生的纤维帽厚度更一致。这些结果表明，ARFI log(VoA) 能够改善相对于 ARFI PD 的纤维帽厚度的区分，并进一步有助于越来越多的证据证明 ARFI 与描绘颈动脉粥样硬化斑块的结构和组成以预测中风风险的总体相关性。