ASSESSMENT OF CHANGES IN RENAL CORTICAL AND MEDULLARY BLOOD FLOW BY CONTRAST U/S

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 目前测量肾血流量和GFR的技术是耗时和麻烦的。它们需要注射放射性物质或输注一种物质数小时，并进行多次尿液和血液采样。因此，这些方法目前在临床实践中不受欢迎，仅用于研究目的。另一方面，超声检查是一种非侵入性和广泛可用的技术，在肾脏学领域有许多用途。近年来，利用微泡造影剂来增强超声图像在不同的医学领域已经变得流行。该技术目前被用于心肌和冠状动脉的成像。一些研究表明，造影剂增强超声（CEU）诊断肾动脉狭窄的准确性与其他传统方法相当。在这项初步研究中，我们将比较CEU在评估高蛋白饮食引起的肾血流量变化方面的准确性与使用健康个体PAH清除率的标准方法。 我们还将评估CEU在评估局部肾皮质和髓质血流变化中的实用性。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Current techniques of measuring renal blood flow and GFR are time consuming and troublesome. They require either injection of a radioactive material or infusion of a substance for several hours with multiple urine and blood sampling. As a result, these methods are currently out of favor to use in clinical practice and are only reserved for research purposes. On the other hand, ultrasonography is a noninvasive and widely available technology with many uses in the field of nephrology. Recently the use of microbubbles as contrast agents to enhance ultrasound images has become popular in different medical fields. This technique is currently being utilized in imaging of the myocardium and coronary arteries. A few studies have demonstrated comparable accuracy of contrast enhanced ultrasound (CEU) to other conventional methods in diagnosing renal artery stenosis. In this pilot study, we will compare the accuracy of CEU in assessing the changes in renal blood flow in response to a high protein diet to the standard method using PAH clearance in healthy individuals. We will also evaluate the utility of CEU in assessing the changes in regional renal blood flow to cortex and medulla.