Measurement of Renal Viscoelastic Properties with Ultrasound

超声测量肾粘弹特性

• 批准号: 9924519
• 负责人: Matthew William Urban
• 金额: $ 61.33万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-07 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9924519
• 关键词: Achievement; Acoustics; Affect; Allografting; Atrophic; Biopsy; Chronic Kidney Failure; Clinic; Clinical; Creatinine; Data; Diagnosis; Diagnostic; Disease; Doppler Ultrasound; End stage renal failure; Equation; Evaluation; Fibrosis; Foundations; Frequencies; Funding; Glomerular Filtration Rate; Goals; Gold; Graft Rejection; Graft Survival; Grant; Health; Health Care Costs; Hemodialysis; Inflammation; Inflammatory; Kidney; Kidney Diseases; Kidney Failure; Kidney Transplantation; Knowledge; Laboratories; Measurement; Measures; Medical; Medical Imaging; Methods; Modeling; Modulus; Monitor; Motion; Nature; Pathology; Patient Monitoring; Patient-Focused Outcomes; Patients; Physiological; Procedures; Process; Progress Reports; Property; Protocols documentation; Publications; Quality of life; Radiation; Renal function; Research; Research Proposals; Risk; Serum; Statistical Data Interpretation; Stress; Structure; Survival Rate; Techniques; Testing; Therapeutic Intervention; Tissue Differentiation; Tissues; Translating; Translations; Tubular formation; Ultrasonography; Waiting Lists; attenuation; base; clinical practice; clinical translation; cost; diagnosis standard; diagnostic accuracy; elastography; experimental study; imaging approach; imaging modality; improved; insight; interstitial; kidney allograft; kidney biopsy; mechanical properties; non-invasive imaging; patient subsets; programs; public health relevance; screening; soft tissue; standard of care; time use; tool; treatment response; viscoelasticity

ABSTRACT/SUMMARY Background: Chronic kidney disease (CKD) encompasses a long-term decrease in function of the kidneys. CKD can progress to kidney failure or end-stage renal disease (ESRD), which is treated by hemodialysis or kidney transplant. Patient and renal graft survival rates have increased over the past two 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, cannot 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 can discriminate healthy versus diseased tissue based on different parameters measured in the tissue. We have found in the previous cycle of this grant that certain elastographic parameters are sensitive to different structural or physiological changes in renal allografts. Linear and nonlinear elastic mechanical properties were found to be sensitive to the presence of interstitial fibrosis while viscoelastic parameters were sensitive to inflammatory processes and tubular atrophy. Based on these findings, we propose the use of quantitative, noninvasive methods to perform a comprehensive multi-parametric elastographic evaluation of renal allografts to evaluate health of the transplanted kidney. Methods: Ultrasound shear wave-based methods use acoustic radiation force 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 velocity of the shear waves can be modified by several parameters including the elastic, viscoelastic, and nonlinear, mechanical properties in the tissue. We will use shear wave elastography (SWE) to measure elastic properties in the kidney using time-of-flight methods. Viscoelastic properties will be measured using a model-based approach by fitting shear wave velocity dispersion to rheological models or a model-free approach that involves extracting measurements of shear wave velocity and attenuation at various frequencies. Lastly, we will use a method called acoustoelasticity, which combines compression of the renal allograft and SWE measurements to estimate the nonlinear elastic modulus from shear modulus data obtained at various levels of applied stress. The parameters extracted from these measurements will be compared with structural (biopsy) and functional measures of kidney health (serum creatinine, estimated glomerular filtration rate, and Doppler ultrasound results) to elucidate how allograft disease changes these parameters. Establishing these relationships will provide a strong foundation for translating these elastographic measurement methods forward for widespread clinical use for assessment of renal allografts. The noninvasive nature of SWE measurements, available on many clinical ultrasound scanners, make them a strong candidate as a tool for reducing the number of biopsies, and to be used for frequent quantitative assessment and monitoring of patients’ responses to treatment, which will lead to reduced healthcare costs and potentially improved patient outcomes. To accomplish these objectives, we propose the following Specific Aims. Aims: 1) Evaluate the use of SWE to measure elastic mechanical properties for the noninvasive assessment of structural and functional changes in renal allografts. 2) Evaluate the use of SWE to measure viscoelastic mechanical properties to assess renal allograft fibrosis, inflammation, and function. 3) Evaluate the use of acoustoelasticity to measure nonlinear elastic mechanical properties to assess pathology and functional changes in renal allografts.

摘要/摘要 背景：慢性肾脏疾病(CKD)包括肾脏功能的长期下降。 慢性肾脏病可进展为肾衰竭或终末期肾脏疾病(ESRD)，可通过血液透析或 肾移植。在过去的二十年里，患者和肾移植的存活率有所提高，但长期以来- 移植物的长期存活率仍然是一个问题。肾活检是诊断肾脏健康的金标准，但 这是一种侵入性手术，不能频繁使用，而且可能会导致并发症。非侵入性指标 肾脏疾病，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力。弹性成像方法可以区分健康 根据在组织中测量的不同参数来对比病变组织。我们在之前的 某些弹性图参数对不同的结构或生理参数敏感的周期 移植肾的变化。研究发现，线性和非线性弹性力学性能对 间质纤维化的存在，而粘弹性参数对炎症过程和 肾小管萎缩。基于这些发现，我们建议使用定量的、非侵入性的方法进行 多参数综合弹性图评价移植肾的健康状况 移植的肾脏。方法：基于超声横波的方法是利用声辐射力来“推” 并产生剪切波。基于超声波的方法被用来检测剪切的传播 在组织中穿行。横波的传播速度可以通过几个参数进行修正。 包括组织中的弹性、粘弹性和非线性机械特性。我们将使用横波 弹性成像(SWE)使用飞行时间法测量肾脏的弹性特性。粘弹性 属性将使用基于模型的方法进行测量，方法是将剪切波速频散拟合到 流变学模型或涉及提取剪切波速测量的无模型方法 以及在不同频率下的衰减。最后，我们将使用一种名为声学弹性的方法，它结合了 移植肾的压缩和SWE测量以估计移植肾的非线性弹性系数 在不同水平的外加应力下获得的剪切模量数据。从这些数据中提取的参数 测量将与肾脏健康的结构(活检)和功能测量(血清)进行比较 肌酐、估计的肾小球滤过率和多普勒超声结果)以阐明同种异体肾移植如何 疾病会改变这些参数。建立这些关系将为 将这些弹性测量方法转化为广泛的临床使用，以评估 异体肾移植。SWE测量的非侵入性，可在许多临床超声上使用 扫描仪，使其成为减少活检次数的有力候选工具，并可用于 经常对患者的治疗反应进行量化评估和监测，这将导致 降低医疗成本，并有可能改善患者的预后。为了达到这些目标，我们 提出以下具体目标。目的：1)评价SWE测量弹性力学性能的应用 用于非侵入性评估移植肾结构和功能变化的特性。2)评估 使用SWE测量粘弹性力学性能来评估移植肾的纤维化，炎症， 和功能。3)评估声弹性测量非线性弹性力学性能的使用 评估同种异体肾移植的病理和功能变化。