CT imaging for the assessment of kidney injury distal to renal artery stenosis

描述（由申请人提供）：在西方世界，血管疾病对发病率和死亡率的影响正在上升。动脉粥样硬化性肾动脉狭窄（ARAS）是慢性肾脏疾病的常见病因，它会加剧肾功能的恶化，并在干预后减弱其恢复。然而，导致这些严重后果的机制尚未确定，部分原因是缺乏能够研究ARAS远端肾脏的技术，以及合适的ARAS实验模型。该建议的假设是动脉粥样硬化通过损害肾功能和加剧氧化应激、炎症和纤维化，阻碍了狭窄的ARAS肾在干预后的恢复，高分辨率计算机断层扫描（CT）技术将有助于探索和表征肾损伤和对血血重建的反应。这一假设将在我们开发和表征的新型单侧ARAS猪模型中得到验证，该模型使用我们改进的独特成像方法来研究单肾功能和结构。电子束CT （EBCT）将量化在体内，在接受经皮腔内肾血管成形术的猪狭窄肾脏中，肾脏区域体积、灌注、GFR、节段小管功能改变的可逆性，以及对挑战的反应。显微ct随后将用于评估原位肾微血管重构，这是动脉粥样硬化的标志。影像学研究将与肾氧化还原状态、炎症和纤维化的体外研究相关联。此外，将通过将ARAS叠加在小管间质损伤或肾小球硬化中来探讨先前存在的肾损伤对血运重建反应的影响。通过长期补充他汀类药物来研究减轻肾损伤的效果，他汀类药物可以减少氧化应激、炎症和纤维化，并可能在干预前后改善肾脏预后。此外，肾脏改变将与肾脏恢复相关，并确定介入成功的潜在预测因素。这些建议的研究可能会极大地促进我们对ARAS肾损伤发病机制的理解，并有助于开发成像策略来检测损伤标志物和确定肾活力的预测因子。因此，这些研究可能有助于肾血管疾病患者的管理。

DESCRIPTION (provided by applicant): The impact of vascular disease on morbidity and mortality is on the rise in the Western world. Atherosclerotic renal artery stenosis (ARAS), a common etiology of chronic kidney disease, amplifies deterioration of renal function and attenuates its recovery following intervention. However, the mechanisms leading to these grave outcomes are yet to be identified, partly due to the lack of techniques capable of studying the kidney distal to ARAS, and of suitable experimental models of ARAS. The hypothesis underlying this proposal is that atherosclerosis blunts the recovery of the stenotic ARAS kidney following intervention by impairing renal function and exacerbating oxidative stress, inflammation, and fibrosis, and that high-resolution computed tomography (CT) techniques would be useful to explore and characterize renal injury and response to revascularization. This hypothesis will be tested in a novel pig model of unilateral ARAS that we have developed and characterized, using unique imaging approaches that we have refined to study single-kidney function and structure. Electron beam CT (EBCT) will quantify in vivo, in the stenotic kidney of pigs undergoing percutaneous transluminal renal angioplasty, the reversibility of alterations in renal regional volume, perfusion, GFR, segmental tubular function, and response to challenge. Micro-CT will be subsequently used to assess in situ renal microvascular remodeling, a hallmark of atherosclerosis. The imaging studies will be correlated with in vitro studies of renal redox status, inflammation, and fibrosis. Furthermore, the impact of preexisting renal injury on the response to revascularization will be explored by superimposing ARAS on tubulointerstitial injury or glomerulosclerosis. The effect of attenuation of renal injury will be studied using chronic supplementation of statins, drugs that decrease oxidative stress, inflammation, and fibrosis, and might improve renal outcomes before as well as after intervention. Moreover, renal alterations will be correlated with renal recovery, and potential predictors of interventional success will be determined. The proposed studies may greatly advance our understanding of the pathogenesis of renal injury in ARAS, and assist in development of imaging strategies to detect injury markers and identify predictors of renal viability. Thus, these studies may contribute towards management of patients with renovascular disease.