首页> 外文期刊>IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control >Effect of red cell clustering and anisotropy on ultrasound blood backscatter: a Monte Carlo study
【24h】

Effect of red cell clustering and anisotropy on ultrasound blood backscatter: a Monte Carlo study

机译:红细胞聚集和各向异性对超声血液反向散射的影响:蒙特卡洛研究

获取原文
获取原文并翻译 | 示例
           

摘要

When flowing at a low shear rate, blood appears hyperechogenic on ultrasound B-scans. The formation of red blood cell (RBC) aggregates that also alters blood viscosity is the microscopic mechanism explaining this acoustical phenomenon. In this study, Monte Carlo simulations were performed to predict how RBC clustering increases ultrasound scattering by blood. A bidimensional Gibbs-Markov random point process parameterized by the adhesion energy /spl epsi/ and an anisotropy index /spl nu/ was used to describe RBC positions for a hematocrit H=40%. The frequency dependence of the backscattering coefficient /spl chi/(f) was computed using Born approximation. The backscattering coefficient /spl chi//sup 0/ at 5 MHz and the spectral slopes and n/sub x/ and n/sub y/ (/spl chi//spl prop/f(n/sub x/) or f(n/sub y/)) measured, respectively, when the insonification is parallel and perpendicular with the RBC cluster axis were then extracted. Under isotropic conditions, /spl chi//sup 0/ increased up to 7 dB with /spl epsi/ and n/sub x/=n/sub y/ decreased from 4.2 to 3.4. Under anisotropic conditions, the backscattering was stronger perpendicularly to aggregate axis, resulting in n/sub x/
机译:当以低剪切速率流动时,血液在超声B扫描中表现出高回声性。红细胞(RBC)聚集体的形成也改变了血液的黏度,是解释这种声学现象的微观机制。在这项研究中,进行了蒙特卡洛模拟以预测RBC聚类如何增加血液对超声的散射。用粘附能/ spl epsi /和各向异性指数/ spl nu /参数化的二维吉布斯-马尔可夫随机点过程用于描述血细胞比容H = 40%的RBC位置。反向散射系数/ spl chi /(f)的频率相关性是使用Born近似计算的。 5 MHz时的背向散射系数/ spl chi // sup 0 /和频谱斜率以及n / sub x /和n / sub y /(/ spl chi // spl prop / f(n / sub x /)或f(然后提取当超声检查与RBC群集轴平行和垂直时分别测量的n / sub y /))。在各向同性条件下,/ spl epsi /使/ spl chi // sup 0 /增加至7 dB,而n / sub x / = n / sub y /从4.2降至3.4。在各向异性条件下,垂直于聚集轴的反向散射更强,从而导致n / sub x /

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号