Loizou Christos P, Pattichis Constantinos S, Pantziaris Marios, Kyriacou Efthyvoulos, Nicolaides Andrew
Department of Electrical, Computer Engineering and InformaticsCyprus University of Technology.
Department of Computer ScienceUniversity of Cyprus.
IEEE J Transl Eng Health Med. 2017 Sep 28;5:1800509. doi: 10.1109/JTEHM.2017.2728662. eCollection 2017.
The objective of this paper was to investigate texture feature variability in ultrasound video of the carotid artery during the cardiac cycle in an attempt to define new discriminatory biomarkers of the vulnerable plaque. More specifically, in this paper, 120 longitudinal ultrasound videos, acquired from 40 normal (N) subjects from the common carotid artery and 40 asymptomatic (A) and 40 symptomatic (S) subjects from the proximal internal carotid artery were investigated. The videos were intensity normalized and despeckled, and the intima-media complex (IMC) (from the N subjects) and the atherosclerotic carotid plaques (from the A and S subjects) were segmented from each video, in order to extract the M-mode image, and the texture features associated with cardiac states of systole and diastole. The main results of this paper can be summarized as follows: 1) texture features varied significantly throughout the cardiac cycle with significant differences identified between the cardiac systolic and cardiac diastolic states; 2) gray scale median was significantly higher at cardiac systole versus diastole for the N, A, and S groups investigated; 3) plaque texture features extracted during the cardiac cycle at the systolic and diastolic states were statistically significantly different between A and S subjects (and can thus be used to discriminate between A and S subjects successfully). The combination of systolic and diastolic features yields better performance than those alone. It is anticipated that the proposed system may aid the physician in clinical practice in classifying between N, A, and S subjects using texture features extracted from ultrasound videos of IMC and carotid artery plaque. However, further evaluation has to be carried out with more videos and additional features.
本文的目的是研究心动周期中颈动脉超声视频中的纹理特征变异性，以期定义易损斑块的新鉴别生物标志物。具体而言，本文研究了从40名正常（N）受试者的颈总动脉以及40名无症状（A）和40名有症状（S）受试者的颈内动脉近端采集的120段纵向超声视频。对视频进行强度归一化和去斑处理，从每个视频中分割出内膜-中膜复合体（IMC）（来自N组受试者）和动脉粥样硬化颈动脉斑块（来自A组和S组受试者），以便提取M型图像以及与心脏收缩期和舒张期状态相关的纹理特征。本文的主要结果可总结如下：1）纹理特征在整个心动周期中变化显著，心脏收缩期和舒张期状态之间存在显著差异；2）在所研究的N、A和S组中，心脏收缩期的灰度中位数显著高于舒张期；3）在心脏周期的收缩期和舒张期提取的斑块纹理特征在A组和S组受试者之间存在统计学显著差异（因此可成功用于区分A组和S组受试者）。收缩期和舒张期特征的组合比单独使用这些特征具有更好的性能。预计所提出的系统可帮助医生在临床实践中使用从IMC和颈动脉斑块超声视频中提取的纹理特征对N、A和S组受试者进行分类。然而，必须使用更多视频和其他特征进行进一步评估。
