MR Angiography and Renography for Renovascular Disease

描述（由申请人提供）：肾血管疾病（RVD）是美国高血压和肾衰竭最常见的潜在可逆原因。它的诊断是有问题的，因为肾动脉狭窄（RAS）本身是不够的诊断。原发性高血压和RAS经常共存，因此x线血管造影等解剖研究不能准确预测对血运重建术的反应。迄今为止，没有一种检测方法能同时提供准确的解剖和功能评估来诊断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测试进一步限制了临床试验。在第一个资助期，我们开发了一种可靠的定量低剂量gd增强MR肾造影方法，用于测量单肾肾小球滤过率（GFR），并实施了一种双注射方法，用于ace抑制剂增强MR肾造影诊断RVD。我们的功能研究可以结合肾脏MRA进行解剖评估，早期结果很有希望。我们还证明了将呋塞米增强的BOLD MR与ACE-I MR肾造影相结合用于测量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，我们建议测试一种全面的解剖和功能MR方案来诊断RVD，并使用MR纵向测量单个肾脏功能结果。广泛的长期目标：通过正确诊断疾病，确定哪些患者可能受益于血运重建治疗，哪些患者应该单独用药，从而降低与RVD引起的高血压和肾衰竭相关的发病率和死亡率。具体目的/方法：(1)确定MRA联合ace抑制剂MR肾造影术和呋塞米- bold MRI诊断RVD的单一综合检查的准确性。我们将对264名受试者进行为期3年的前瞻性研究，并将MR结果与MRA和x线血管造影结果进行比较，以血压和肾功能对血运重建措施的反应作为参考标准。(2)采用磁共振肾造影和速尿- bold MRI进行纵向研究，研究接受血运重建术或接受医学治疗的RAS患者的单侧和对侧单肾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血管重建术后肾功能的亚临床改善和RVD患者医学管理后的亚临床下降。综上所述，我们的研究极有可能表明，全面的MR检查，通过在单一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.