In vivo carotid strain imaging using principal strains in longitudinal view
In vivo carotid strain imaging using principal strains in longitudinal view
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DOI：
10.1088/2057-1976/ab15c9
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发表时间：
2019-04-01
影响因子：
1.4
通讯作者：
Varghese, T.
中科院分区：
文献类型：
--
作者：
Meshram, N. H.;Mitchell, C. C.;Varghese, T.
颈动脉斑块破裂可能导致中风或短暂性脑缺血发作，对患者来说可能是毁灭性的。超声应变成像提供了一种非侵入性方法来识别可能破裂的不稳定斑块。颈动脉斑块的轴向、侧向和剪切应变已被证明与颈动脉斑块不稳定有关。最近，人们有兴趣使用不依赖于颈动脉松弛角度的主应变来定量斑块纵向上的不稳定性。在这项工作中，比较了角度相关的轴向应变、横向应变和剪切应变以及与轴无关的主应变之间的关系。定义了三个应变指数，(1)平均平均应变(AMS)，(2)最大平均应变(MMS)和(3)平均标准差(MSD)，以确定这五种应变图像类型之间的关系。所有患者的最大主应变与轴向应变相比显示出最高的应变值，其线性回归斜率为1.6，对于AMS，y截距为2.4%。AMS的最大剪切应变与剪切应变相比斜率为1.15，y截距为0.21%。其次，研究了动脉在斑块部位遮盖的角度--声化角的影响。患者分为5度以下组31例，5~10度组24例，10度以上组21例。比较角度依赖应变值和独立应变值之间的关系时，三个角度组之间的光化角度没有显著差异。
Carotid plaque rupture can result in stroke or transient ischemic attack that can be devastating for patients. Ultrasound strain imaging provides a noninvasive method to identify unstable plaque likely to rupture. Axial, lateral and shear strains in carotid plaque have been shown to be linked to carotid plaque instability. Recently, there has been interest in using principal strains, which do not depend on angle of insonification of the carotid artery for quantifying instability in plaque along the longitudinal view. In this work relationships between angle dependent axial, lateral and shear strain along with axis independent principal strains are compared. Three strain indices were defined, (1) Average Mean Strain (AMS), (2) Maximum Mean Strain (MMS) and (3) Mean Standard Deviation (MSD) to identify relationships between these five strain image types in a group of 76 in vivo patients. The maximum principal strain demonstrated the highest strain values when compared to axial strain for all patients with a linear regression slope of 1.6 and a y intercept of 2.4 percent strain for AMS. The maximum shear strain when compared to shear strain had a slope of 1.15 and a y intercept of 0.21 percent for AMS. Next, the effect of insonification angle, which is the angle subtended by the artery at the location of plaque was studied. Patients were divided into three sub groups, i.e. less than 5 degrees (n = 31), between 5 and 10 degrees (n = 24) and above 10 degrees (n = 21). The angle of insonification did not make a significant difference between the three angle groups when comparing the relationship between the angle dependent and independent strain values.