Steinbuch J, Schreuder F H B M, Reesink K D, Hoeks A P G, Mess W H
Biomedical Engineering, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.
Radiology, Maastricht University Medical Center, Maastricht, The Netherlands; Clinical Neurophysiology, Maastricht University Medical Center, Maastricht, The Netherlands; Neurology, Maastricht University Medical Centre, Maastricht, The Netherlands.
Ultrasound Med Biol. 2018 May;44(5):986-994. doi: 10.1016/j.ultrasmedbio.2017.12.013. Epub 2018 Feb 21.
To properly assess morphologic and dynamic parameters of arteries and plaques, we propose the concept of orthogonal distance measurements, that is, measurements made perpendicular to the local lumen axis rather than along the ultrasound beam (vertical direction for a linear array). The aim of this study was to compare orthogonal and vertical artery and lumen diameters at the site of a plaque in the common carotid artery (CCA). Moreover, we investigated the interrelationship of orthogonal diameters and plaque size and the association of artery parameters with plaque echogenicity. In 29 patients, we acquired a longitudinal B-mode ultrasound recording of plaques at the posterior CCA wall. After semi-automatic segmentation of end-diastolic frames, diameters were extracted orthogonally along the lumen axis. To establish inter-observer variability of diameters obtained at the location of maximal plaque thickness, a second observer repeated the analysis (subset N = 21). Orthogonal adventitia-adventitia and lumen diameters could be determined with good precision (coefficient of variation: 1%-5%. However, the precision of the change in lumen diameter from diastole to systole (distension) at the site of the plaque was poor (21%-50%). The orthogonal lumen diameter was significantly smaller than the vertical lumen diameter (p <0.001). Surprisingly, the plaques did not cause outward remodeling, that is, a local increase in adventitia-adventitia distance at the site of the plaque. The intra- and inter-observer precision of diastolic-systolic plaque compression was poor and of the same order as the standard deviation of plaque compression. The orthogonal relative lumen distension was significantly lower for echogenic plaques, indicating a higher stiffness, than for echolucent plaques (p <0.01). In conclusion, we illustrated the feasibility of extracting orthogonal CCA and plaque dimensions, albeit that the proposed approach is inadequate to quantify plaque compression.
为了准确评估动脉和斑块的形态及动态参数，我们提出了正交距离测量的概念，即垂直于局部管腔轴而非沿着超声束（线性阵列的垂直方向）进行测量。本研究的目的是比较颈总动脉（CCA）斑块部位的正交和垂直动脉及管腔直径。此外，我们研究了正交直径与斑块大小的相互关系以及动脉参数与斑块回声性的关联。在29例患者中，我们获取了CCA后壁斑块的纵向B超记录。在对舒张末期帧进行半自动分割后，沿管腔轴正交提取直径。为确定在斑块最大厚度位置获得的直径的观察者间变异性，另一位观察者重复了分析（子集N = 21）。正交外膜-外膜和管腔直径能够以良好的精度确定（变异系数：1%-5%）。然而，斑块部位管腔直径从舒张期到收缩期的变化（扩张）精度较差（21%-50%）。正交管腔直径显著小于垂直管腔直径（p <0.001）。令人惊讶的是，斑块并未引起向外重塑，即在斑块部位外膜-外膜距离局部增加。舒张期-收缩期斑块压缩的观察者内和观察者间精度较差，且与斑块压缩的标准差处于同一量级。与无回声斑块相比，有回声斑块的正交相对管腔扩张显著更低，表明其硬度更高（p <0.01）。总之，我们证明了提取正交CCA和斑块尺寸的可行性，尽管所提出的方法不足以量化斑块压缩。
