Measurement of Renal Viscoelastic Properties with Ultrasound

描述(申请人提供)：背景：慢性肾脏病(CKD)包括肾脏功能的长期下降，在20岁及以上的美国成年人中有11.5%，即超过2000万人。慢性肾脏病可进展为肾功能衰竭或终末期肾病(ESRD)。截至2008年底，547,982名患者正在接受终末期肾病治疗，其中包括血液透析或肾移植。在过去的50年里，患者和肾移植的存活率有所提高，但移植物的长期存活率仍然很高。 一个问题。肾活检是诊断肾脏健康的金标准，但它是一种侵入性操作，不能频繁使用，而且会引起并发症。肾脏疾病的非侵入性指标，包括血清肌酐水平、肾小球滤过率和经典医学成像，可以为肾脏疾病状态提供一定的洞察。弹性成像方法是一种根据组织的弹性或粘性来区分健康组织和疾病组织的方法。当组织的结构因疾病过程而改变时，其功能和粘弹性也会改变。我们建议使用一种称为剪切波色散超声测振法(SDUV)的定量、非侵入性方法来测量这些量来评估肾脏健康状况。方法：SDUV使用聚焦的超声波“推动”组织并产生剪切波。基于超声波的方法被用来检测横波在组织中的传播。横波的传播速度随频率变化，这种现象称为色散。这种剪切波速频散可以用来评估组织的剪切弹性和粘性。对包括肝、肾、骨骼肌、前列腺、心脏和动脉在内的许多不同类型的组织的研究表明，SDUV可以作为一种有用的方法来定量评估组织的粘弹性特性。SDUV测量是一种非侵入性、快速、定位于一小块组织的测量方法。这种非侵入性测量技术可以作为减少活检次数的一线筛查工具。此外，它还可以作为一个量化指标，对接受治疗方案的患者进行频繁评估和监测，以跟踪进展情况。在这个项目中开发的SDUV技术可以在现代超声扫描仪上实施，只需修改软件，即可广泛用于临床翻译。目的：1.开发分析方法并优化SDUV的实施，以表征自体和移植的人肾的粘弹性。2.研究SDUV法测量健康供者肾脏和慢性肾脏疾病患者肾脏粘弹性的关系。3.研究粘弹性材料特性的SDUV测量与临床肾移植排斥反应评估指标的关系。

DESCRIPTION (provided by applicant): Background: Chronic kidney disease (CKD) encompasses a long-term decrease in function of the kidneys which afflicts 11.5% in American adults aged 20 and over, which is more than 20 million people. CKD can progress to kidney failure or end-stage renal disease (ESRD). At the end of 2008, 547,982 patients were receiving ESRD therapy, which includes hemodialysis or kidney transplant. Patient and renal graft survival rates have increased over the past five decades, but long-term survival of grafts is still an issue. Renal biopsy is the gold standard for diagnosis of kidney health, but is an invasive procedure, can not be used frequently, and can cause complications. Noninvasive indicators of kidney disease including levels of serum creatinine, glomerular filtration rate, and classical medical imaging can provide certain insights into kidney disease state. Elasticity imaging methods are emerging as a way to discriminate healthy versus diseased tissue based on the elasticity or viscosity of the tissue. When the structure of tissue changes due to disease processes, the function and viscoelastic properties also change. We propose the use of a quantitative, noninvasive method called shearwave dispersion ultrasound vibrometry (SDUV) to measure these quantities for assessment of renal health. Method: SDUV uses focused ultrasound to "push" the tissue and create shear waves. Ultrasound-based methods are used to detect the propagation of the shear waves through the tissue. The propagation speed of the shear waves varies with frequency, a phenomenon known as dispersion. This shear wave speed dispersion can be used to evaluate the shear elasticity and viscosity of the tissue. Studies in many different types of tissue including liver, kidney, skeletal muscle, prostate, heart and arteries have shown that SDUV can be a useful method for quantitatively evaluating the viscoelastic properties of tissue. SDUV measurements are noninvasive, fast, and localized to a small region of tissue. This noninvasive measurement technique can be suitable as a first-line screening tool to reduce the numbers of biopsies. Additionally, it can be used as a quantitative indicator for frequent assessment and monitoring of patients undergoing treatment regimens to track progress. SDUV techniques developed in this project could be implemented on modern ultrasound scanners with software modifications for widespread clinical translation. Aims: 1. Develop analytic methods and optimize implementation of SDUV for viscoelastic characterization of the native and transplanted human kidney. 2. Study the relationships between SDUV measurements of the viscoelastic properties of native kidneys of healthy kidney donors and patients with chronic kidney disease. 3. Study the relationship between SDUV measurements of viscoelastic material properties with clinical measures for assessment of kidney transplant rejection.