MR Angiography and Renography for Renovascular Disease

描述（由申请方提供）：肾血管疾病（RVD）是美国最常见的潜在可逆性高血压和肾衰竭原因。其诊断是有问题的，因为单独的肾动脉狭窄（RAS）不足以诊断。原发性高血压和RAS经常共存，因此解剖学研究如X线血管造影不能准确预测血运重建的反应。迄今为止，没有测试提供准确的解剖和功能评估，以诊断RVD。RAS患者的管理也是一个难题。无法区分RVD和偶发RAS也导致了广泛的不确定性治疗，缺乏检测个体肾脏反应的敏感试验进一步限制了临床试验。在第一个资助期，我们开发了一种稳健的定量低剂量Gd增强MR肾成像方法，用于测量单肾肾小球滤过率（GFR），并实施了ACE抑制剂增强MR肾成像的双注射方法，以诊断RVD。我们的功能研究可以与肾脏MRA结合进行解剖评估，具有良好的早期结果。我们还显示了速尿增强BOLD MR与ACE-I MR肾造影结合测量RAS患者肾缺血的可行性，并研究了新的非Gd增强MRA方法。在下一个资助期内，我们建议测试一个全面的解剖和功能MR协议，以诊断RVD，并纵向使用MR来测量单肾功能结果。广泛的长期目标：通过正确诊断疾病并确定哪些患者可能从血运重建治疗中获益以及哪些患者应单独接受药物治疗，降低与RVD引起的高血压和肾衰竭相关的发病率和死亡率。具体目标/方法：（1）确定MRA、ACE抑制剂MR肾造影和速尿-BOLD MRI联合诊断RVD的准确性。我们将在264名受试者中进行一项为期3年的前瞻性研究，并将我们的MR结果与MRA和X线血管造影进行比较，使用血压和肾功能的血运重建反应作为参考标准。(2)使用MR肾造影和呋塞米-BOLD MRI进行纵向研究，以研究接受血运重建或药物治疗的RAS患者的同侧和对侧单肾GFR。我们将使用单肾GFR和氧合的测量来评估对治疗的反应，假设我们的方法将检测到血管重建后肾功能的亚临床改善和药物治疗的RVD患者的亚临床下降。在其结论中，我们的研究极有可能表明，全面的MR检查，通过在一次测试中独特地提供解剖和功能信息，将准确诊断RVD，并为测量治疗后的结果提供有价值的工具。

DESCRIPTION (provided by applicant): Renovascular disease (RVD) is the most common potentially reversible cause of hypertension and renal failure in the US. Its diagnosis is problematic because renal artery stenosis (RAS) alone is insufficient for diagnosis. Essential hypertension and RAS often coexist, hence anatomic studies such as x-ray angiography do not accurately predict response to revascularization. To date, no test provides both accurate anatomic and functional assessment to diagnose RVD. Management of RAS patients is also a dilemma. The inability to differentiate RVD from incidental RAS has also contributed to the widespread uncertainty treatment, and lack of a sensitive test for detecting individual kidney response has further limited clinical trials. In the first funding period we developed a robust and quantitative low dose Gd-enhanced MR renography method for measuring single kidney glomerular filtration rate (GFR) and implemented a dual-injection method for ACE-inhibitor- enhanced MR renography to diagnose RVD. Our functional study can be performed in conjunction with renal MRA for anatomic evaluation with promising early results. We have also shown the feasibility of combining furosemide-enhanced BOLD MR with ACE-I MR renography for measuring renal ischemia in patients with RAS and have also investigated new non-Gd-enhanced MRA methods. In the next funding period, we propose to test a comprehensive-anatomic and functional-MR protocol to diagnose RVD and also to use MR longitudinally to measure single kidney functional outcomes. Broad, long-term objectives: To reduce the morbidity and mortality associated with hypertension and renal failure due to RVD by correctly diagnosing the disease and by determining which patients are likely to benefit from revascularization therapy and which patients should be treated with medication alone. Specific Aims/Methods: (1) To determine the accuracy of a single comprehensive exam that combines MRA with ACE-inhibitor MR renography and furosemide-BOLD MRI for the diagnosis of RVD. We will perform a prospective study in 264 subjects over 3 years and compare our MR results with MRA and x-ray angiography, using response to revascularization measures of blood pressure and renal function as the reference standard. (2) To perform a longitudinal study using MR renography and furosemide-BOLD MRI to study ipsi- and contralateral single kidney GFR in RAS patients who undergo revascularization or who are medically managed. We will use measurements of single kidney GFR and oxygenation to assess responses to therapies with the hypothesis that our methods will detect otherwise subclinical improvements in renal function after revascularization and otherwise subclinical declines in patients with RVD managed medically. At its conclusion, our study highly likely to show that a comprehensive MR exam, by uniquely providing both anatomic and functional information in a single test, will accurately diagnose RVD and provide a valuable tool for measuring outcomes following therapy.