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

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 目前测量肾血流量和肾小球滤过率的技术既费时又麻烦。它们需要注射放射性物质或通过多次尿液和血液采样将一种物质输注几个小时。因此，这些方法目前不适合用于临床实践，仅用于研究目的。另一方面，超声是一种非侵入性的广泛使用的技术，在肾脏病领域有许多用途。近年来，利用微泡作为造影剂来增强超声图像在不同的医学领域得到了广泛的应用。这项技术目前正被用于心肌和冠状动脉的成像。少数研究表明，在诊断肾动脉狭窄方面，对比增强超声(CEU)与其他常规方法具有相当的准确性。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变化方面的准确性，并与健康个体使用PAH清除的标准方法进行比较。我们还将评估CEU在评估流向皮质和髓质的局部肾血流变化方面的作用。

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.