肠缺血是一种可导致肠缺血、坏死甚至危及生命的常见疾病，常由血管病变或血流灌注不足导致，血流动力学改变导致肠缺血改变，早期诊断对该疾病预后至关重要。因此实现肠系膜上动脉的血流动力学定量分析对该病的早期诊断及治疗至关重要。目前，肠系膜上动脉血流动力学主要借助彩色多普勒超声（CDFI）及MRI电影相位对比法（Cine PC）评估，然而上述方法均无法清晰显示血管全程形态且检查结果易受被检者及操作者影响。MR非对比剂增强血管成像联合多反转脉冲空间标记技术（SLEEK）可实现多部位血管成像，研究发现不同血管最佳成像血流抑制反转时间（BSP TI）与其血流速度有一定相关性。因此，本研究拟通过SLEEK技术对血流量化模型及肠系膜上动脉进行成像，研究BSP TI与血流速度之间的函数关系，以期为SLEEK肠系膜上动脉血流量化评估的可行性提供理论基础，从而评估疾病状态下血流动力学改变，为疾病诊断提供更有力证据。

Intestinal ischemia, a common disease caused by various diseases and vascular lesions can lead to intestinal necrosis or even life threatening. Frequently seen ischemic symptoms as hemodynamic changes without obvious stenosis. Therefore, quantitative hemodynamic analysis is essential for early diagnosis and treatment. At present, superior mesenteric artery （SMA）hemodynamic changes was assessed mainly by color Doppler ultrasound (CDFI) but was largely disturbed by intestinal gas and other interference factors. Researches shows that a new unenhanced MR angiography (MRA) sequence, spatial labeling with multiple inversion pulses (SLEEK), having been applied to multiple sites of vascular imaging demonstrated different best blood suppression inversion time(BSP TI) for different blood velocity. The purposes of this study is to determine the relationship of BSP TI and blood velocity in vessel model and human superior mesenteric artery and provide theoretical basis for quantitative assessment of superior mesenteric artery blood flow using non contrast enhanced MR.