Measurement of Renal Viscoelastic Properties with Ultrasound

描述（由申请人提供）：背景：慢性肾脏疾病（CKD）包括肾脏功能的长期下降，其在20岁及以上的美国成年人中占11.5%，超过2000万人。CKD可进展为肾衰竭或终末期肾病（ESRD）。截至2008年底，有547，982名患者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，患者和肾移植物的存活率有所提高，但移植物的长期存活率仍然很低。 问题肾活检是诊断肾脏健康的金标准，但是一种侵入性操作，不能经常使用，并且可能引起并发症。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提供对肾脏疾病状态的某些见解。弹性成像方法作为一种基于组织的弹性或粘性来区分健康组织与患病组织的方式而出现。当组织的结构由于疾病过程而改变时，功能和粘弹性也改变。我们建议使用一种定量的，非侵入性的方法，称为剪切波色散超声振动测量（SDUV）来测量这些数量的肾脏健康评估。方法：SDUV使用聚焦超声“推动”组织并产生剪切波。基于超声的方法用于检测剪切波通过组织的传播。剪切波的传播速度随频率而变化，这种现象称为色散。该剪切波速度分散可用于评估组织的剪切弹性和粘度。在许多不同类型的组织，包括肝脏，肾脏，骨骼肌，前列腺，心脏和动脉的研究表明，SDUV可以是一个有用的方法，定量评估组织的粘弹性。SDUV测量是非侵入性的，快速的，并且定位于组织的小区域。这种非侵入性测量技术可以作为一线筛选工具，以减少活检的数量。此外，它还可以作为一个定量指标，用于频繁评估和监测接受治疗方案的患者，以跟踪进展。本项目中开发的SDUV技术可以在现代超声扫描仪上实现，并对软件进行修改以进行广泛的临床翻译。目的：1.开发分析方法并优化SDUV的实施，用于天然和移植人体肾脏的粘弹性表征。2.研究SDUV测量健康供肾者和慢性肾脏疾病患者的天然肾脏的粘弹性之间的关系。3.研究粘弹性材料特性的SDUV测量与评估肾移植排斥反应的临床测量之间的关系。

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.