Shear wave absolute vibro-elastography of the liver: method optimization and characterization

肝脏剪切波绝对振动弹性成像：方法优化和表征

• 批准号: 537496-2018
• 负责人: Salcudean, Septimiu
• 金额: $ 4.91万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=699391
• 关键词: Shear; wave; absolute; vibro; elastography

Liver disease management can benefit from the measurement of liver stiffness and liver fat content. Liver stiffness can be assessed without biopsy by measuring the propagation speed of shear waves in tissue using magnetic resonance elastography (MRE), a technique in which a steady vibration is applied to tissue and the shear wave pattern throughout the tissue volume is measured. Fat content can also be measured with MR imaging. What is needed is MRI quality measurements at the cost and accessibility offered by ultrasound. In recent work with our partner, we have demonstrated that an electronically scanned 3D ultrasound transducer can be used to accurately measure steady-state wave motion induced by multi-frequency steady-state vibrations in tissue-mimicking phantoms and in healthy volunteers. The technique developed, called S-WAVE, currently does not provide real-time feedback to the operator on the quality of the image acquisition and does not provide the stiffness map in real time. Furthermore, imaging of patients is different than imaging healthy volunteers because their livers are much stiffer and have much higher fat content, and the patients involved are often large which makes scanning them difficult, whether by MRI or ultrasound. With our partner in this project, we will: (1) develop methods for real-time display of 2D shear-wave images during S-WAVE data acquisition and of the computed stiffness maps, and we will evaluate the usability and repeatability of the system in healthy volunteers; (2) compare shear and loss moduli acquired with S-WAVE and MRE, by using new image registration techniques, and also develop methods for imaging both elasticity and viscosity and their dependence on frequency; and (3) develop a model of fat content from ultrasound attenuation and shear wave attenuation, with MRI as the gold standard. To carry out the modeling required under (2) and (3), we will acquire healthy volunteer and patient data with the system developed in (1). Our technique has the advantage of being able to image the liver volume at depth, through a much simpler examination than by MRI. Its successful implementation has the potential to make a significant impact.

肝病管理可以从肝脏硬度和肝脏脂肪含量的测量中受益。通过使用磁共振弹性成像（MRE）测量剪切波在组织中的传播速度，可以在没有活检的情况下评估肝脏硬度，磁共振弹性成像是一种将稳定振动施加到组织并测量整个组织体积中的剪切波图案的技术。脂肪含量也可以通过MR成像来测量。需要的是MRI质量测量的成本和超声提供的可及性。 在最近与我们的合作伙伴的工作中，我们已经证明，电子扫描的3D超声换能器可用于准确测量稳态波动引起的多频稳态振动在组织模仿幻影和健康志愿者。所开发的称为S-WAVE的技术目前不向操作者提供关于图像采集质量的实时反馈，并且不提供真实的时间的刚度图。此外，患者的成像与健康志愿者的成像不同，因为他们的肝脏更硬，脂肪含量更高，并且所涉及的患者通常很大，这使得扫描他们很困难，无论是通过MRI还是超声。我们将与该项目的合作伙伴一起：（1）开发在S-WAVE数据采集期间实时显示2D剪切波图像和计算刚度图的方法，并评估该系统在健康志愿者中的可用性和可重复性;（2）通过使用新的图像配准技术，比较S-WAVE和MRE获得的剪切模量和损耗模量，并开发弹性和粘性成像方法及其对频率的依赖性;（3）以MRI为金标准，开发基于超声衰减和剪切波衰减的脂肪含量模型。为了进行（2）和（3）中所需的建模，我们将使用（1）中开发的系统获取健康志愿者和患者数据。我们的技术的优点是能够成像的肝脏体积在深度，通过一个简单得多的检查比MRI。其成功实施有可能产生重大影响。