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Flow imaging using MRI: Quantification and analysis.

机译:使用MRI的流量成像:量化和分析。

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摘要

A complex and challenging problem in flow study is to obtain quantitative flow information in opaque systems, for example, blood flow in biological systems and flow channels in chemical reactors. In this regard, MRI is superior to the conventional optical flow imaging or ultrasonic Doppler imaging. However, for high speed flows, complex flow behaviors and turbulences make it difficult to image and analyze the flows.;In MR flow imaging, MR tagging technique has demonstrated its ability to simultaneously visualize motion in a sequence of images. Moreover, a quantification method, namely HARmonic Phase (HARP) analysis, can extract a dense velocity field from tagged MR image sequence with minimal manual intervention. In this work, we developed and validated two new MRI methods for quantification of very rapid flows. First, HARP was integrated with a fast MRI imaging method called SEA (Single Echo Acquisition) to image and analyze high velocity flows. Second, an improved HARP method was developed to deal with tag fading and data noise in the raw MRI data. Specifically, a regularization method that incorporates the law of flow dynamics in the HARP analysis was developed. Finally, the methods were validated using results from the computational fluid dynamics (CFD) and the conventional optimal flow imaging based on particle image velocimetry (PIV). The results demonstrated the improvement from the quantification using solely the conventional HARP method.
机译:流量研究中的一个复杂而具有挑战性的问题是在不透明的系统中获得定量的流量信息,例如生物系统中的血流和化学反应器中的流道。在这方面,MRI优于常规的光流成像或超声多普勒成像。但是,对于高速流,复杂的流行为和湍流使其难以对流进行成像和分析。在MR流成像中,MR标签技术已证明其能够同时可视化一系列图像中的运动。此外,量化方法,即谐波相位(HARP)分析,可以用最少的人工干预从标记的MR图像序列中提取密集的速度场。在这项工作中,我们开发并验证了两种新的MRI方法,用于定量非常快速的流量。首先,HARP与称为SEA(单回波采集)的快速MRI成像方法集成在一起,以成像和分析高速流动。其次,开发了一种改进的HARP方法来处理原始MRI数据中的标签褪色和数据噪声。具体而言,开发了一种在HARP分析中纳入流动动力学定律的正则化方法。最后,使用计算流体动力学(CFD)和基于粒子图像测速(PIV)的常规最佳流动成像的结果对方法进行了验证。结果表明,仅使用常规HARP方法进行定量分析可带来改进。

著录项

  • 作者

    Jiraraksopakun, Yuttapong.;

  • 作者单位

    Texas A&M University.;

  • 授予单位 Texas A&M University.;
  • 学科 Engineering Biomedical.;Engineering Electronics and Electrical.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 199 p.
  • 总页数 199
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

  • 入库时间 2022-08-17 11:38:19

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