Non-Contrast Magnetic Resonance Angiography of Peripheral Vascular Disease

描述(申请人提供)：外周血管疾病(PVD)在美国影响着800万人，导致显著的发病率，并与心血管死亡有关。鉴于许多PVD患者还患有肾功能受损，由于担心肾源性系统性纤维化(NSF)的风险，在使用CE-MRA时必须谨慎，NSF是一种严重的潜在致命疾病。最近，非增强MRA技术被提出以消除NSF的风险。这项建议的总体目标是实施一种对收缩峰值血流时间不敏感的非对比剂外周MRA的方法学；此外，该技术应该快速、对患者运动不敏感和准确。为此，我们实现了一种新的方法，该方法由脂肪抑制、单次激发2D饱和恢复真FISP(SR-TFI)脉冲序列组成。虽然这种方法用于非对比MRA之前还没有报道，但我们最初的临床试验显示，即使在存在严重的PVD的情况下，也有很好的结果。该方法不需要流动模式的先验知识，并且不需要电影MRI来确定峰值流速的时间，这是FBI的要求。此外，该方法对患者运动的敏感度低于FBI，并且已被证明对盆腔动脉的成像是可靠的。对于不可能将数据采集与心脏周期同步的一小部分患者(例如，由于房颤或其他心律失常)，我们建议使用非门控Ghost MRA。Ghost MRA使用脉动血流产生的Ghost伪影来创建没有背景组织信号贡献的MRA。我们的具体目标是：具体目标1：优化外周动脉多站血流不敏感SR-TFI，总采集时间为10分钟，空间分辨率为1-2 mm~3。具体目标2：实现外周动脉的多站血流依赖(Ghost)MRA，图像采集时间为每个站5分钟，空间分辨率约为1 mm。具体目标3：与CE-MRA和/或X光DSA比较，评价患者的平扫MRA 与公共健康相关：我们已经开发了一套新技术，将在很大程度上消除在磁共振血管成像过程中为了诊断周围血管疾病而使用造影剂的需要。这项研究将导致更好的图像质量，更高的诊断准确性，更低的手术成本，并提高患者的安全性。

DESCRIPTION (provided by applicant): Peripheral vascular disease (PVD) affects 8 million people in the United States, causes significant morbidity, and is associated with cardiovascular mortality. Given that many patients with PVD also suffer from impaired renal function, one must exercise caution in using CE-MRA because of concerns about the risks of nephrogenic systemic fibrosis (NSF), a serious and potentially lethal disorder. Recently, non-enhanced MRA techniques have been proposed to eliminate the risk of NSF. The overall goal of this proposal is to implement a methodology for non-contrast peripheral MRA that is insensitive to the timing of peak systolic flow; moreover, the technology should be fast, insensitive to patient motion, and accurate. For this purpose, we have implemented a novel approach consisting of a fat suppressed, single shot 2D saturation-recovery trueFISP (SR-TFI) pulse sequence. Although this approach for non-contrast MRA has not been previously reported, our initial clinical trials demonstrate excellent results even in the presence of severe PVD. The method does not require prior knowledge of flow patterns and eliminates the need for cine MRI to determine the timing of peak flow velocity, a requirement for FBI. Moreover, the method is less sensitive to patient motion than FBI and has proven robust for imaging of the pelvic arteries. For the small subset of patients in whom it is not possible to synchronize the data acquisition to the cardiac cycle (e.g. due to atrial fibrillation or other cardiac arrhythmias), we propose the use of ungated Ghost MRA. Ghost MRA uses the ghost artifacts generated by pulsatile flow to create an MRA with no signal contribution from background tissues. Our specific aims are: Specific Aim 1: To optimize multi-station flow-insensitive SR-TFI of the peripheral arteries with a total acquisition time < 10 minutes using spatial resolution on the order of 1-2 mm3. Specific Aim 2: To implement multi-station flow-dependent (Ghost) MRA of the peripheral arteries with an image acquisition time < 5 minutes per station using spatial resolution on the order of 1 mm. Specific Aim 3: Evaluate non-contrast MRA in comparison with CE-MRA and/or x-ray DSA in patients PUBLIC HEALTH RELEVANCE: We have developed a set of novel technologies that will largely eliminate the need to administer contrast agents during magnetic resonance angiography in order to diagnose peripheral vascular disease. This study will result in better image quality, greater diagnostic accuracy, lower procedure cost, and enhanced patient safety.