Golemati Spyretta, Stoitsis John S, Gastounioti Aimilia, Dimopoulos Alexandros C, Koropouli Vassiliki, Nikita Konstantina S
First Intensive Care Unit, Medical School, National and Kapodistrian University of Athens, Athens, Greece.
IEEE Trans Inf Technol Biomed. 2012 Sep;16(5):852-8. doi: 10.1109/TITB.2012.2193411. Epub 2012 Apr 4.
Motion of the carotid artery wall is important for the quantification of arterial elasticity and contractility and can be estimated with a number of techniques. In this paper, a framework for quantitative evaluation of motion analysis techniques from B-mode ultrasound images is introduced. Six synthetic sequences were produced using 1) a real image corrupted by Gaussian and speckle noise of 25 and 15 dB, and 2) the ultrasound simulation package Field II. In both cases, a mathematical model was used, which simulated the motion of the arterial wall layers and the surrounding tissue, in the radial and longitudinal directions. The performance of four techniques, namely optical flow (OF (HS)), weighted least-squares optical flow (OF (LK(WLS))), block matching (BM), and affine block motion model (ABMM), was investigated in the context of this framework. The average warping indices were lowest for OF (LK(WLS)) (1.75 pixels), slightly higher for ABMM (2.01 pixels), and highest for BM (6.57 pixels) and OF (HS) (11.57 pixels). Due to its superior performance, OF (LK(WLS)) was used to quantify motion of selected regions of the arterial wall in real ultrasound image sequences of the carotid artery. Preliminary results indicate that OF (LK(WLS)) is promising, because it efficiently quantified radial, longitudinal, and shear strains in healthy adults and diseased subjects.
颈动脉壁的运动对于动脉弹性和收缩性的量化很重要，并且可以通过多种技术进行估计。本文介绍了一种用于从B模式超声图像定量评估运动分析技术的框架。使用1）一幅被25dB高斯噪声和15dB散斑噪声破坏的真实图像，以及2）超声模拟软件包Field II生成了六个合成序列。在这两种情况下，都使用了一个数学模型，该模型模拟了动脉壁层和周围组织在径向和纵向的运动。在这个框架下研究了四种技术的性能，即光流（OF(HS)）、加权最小二乘光流（OF(LK(WLS))）、块匹配（BM）和仿射块运动模型（ABMM）。OF(LK(WLS))的平均翘曲指数最低（1.75像素），ABMM稍高（2.01像素），BM（6.57像素）和OF(HS)（11.57像素）最高。由于其优越的性能，OF(LK(WLS))被用于量化颈动脉真实超声图像序列中动脉壁选定区域的运动。初步结果表明，OF(LK(WLS))很有前景，因为它能有效地量化健康成年人和患病受试者的径向、纵向和剪切应变。
