Non-Contrast-Enhanced Peripheral MR Angiography

非对比增强外周磁共振血管造影

• 批准号: 8249055
• 负责人: VIVIAN S. LEE
• 金额: $ 62.02万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-15 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8249055
• 关键词: Non; Contrast; Enhanced; Peripheral; MR

DESCRIPTION (provided by applicant): Lower extremity peripheral arterial disease (PAD) is a major cause of morbidity and mortality in the U.S., with an estimated prevalence up to 20% in those over 75 years. Gadolinium-enhanced MR angiography (MRA) has emerged as a highly accurate, less invasive approach that has replaced DSA in many diagnostic settings. Recently, gadolinium administration has been linked to the development of nephrogenic systemic fibrosis (NSF) in patients with renal insufficiency. Development of MRA techniques that do not require gadolinium contrast is vitally important for the 8 - 38% of PAD patients with renal insufficiency. A promising non- contrast MRA technique, ECG-FSE, uses an ECG-triggered 3D fast spin echo sequence, which exploits differences in arterial and venous flow during the cardiac cycle. From preliminary experience with ECG-FSE, we identified key factors that compromise image quality in clinical patients about 50% of the time: (a) application of a single set of imaging parameters to both legs despite differences in flow characteristics and (b) relatively long FSE acquisition windows, which contribute to image artifacts. In this proposal, we describe a new approach, VFA-FSE, which incorporates a series of technical improvements including use of variable flip angle FSE, parallel imaging, and separate sagittal acquisitions for each leg to overcome these limitations. Our aims are (1) To systematically develop, test, and refine peripheral vascular 3D VFA-FSE MRA using pulsatile flow phantoms and human subjects, (2) To develop and test dynamic 4D VFA-FSE imaging that incorporates variable trigger delay and variable flow-spoiling for improved infragenual vessel evaluation and (3) To test prospectively an optimized 3 station VFA-FSE protocol with infragenual 4D VFA-FSE in 200 PAD patients, and to demonstrate comparable accuracy with bolus-chase and Gd-MRA and infragenual time-resolved Gd-MRA. The overarching goals of our research are to develop and validate a robust and artifact-free ECG-triggered variable flip angle FSE technique for peripheral MRA that provides accurate depictions of anatomy and disease without exposing patients to an exogenous contrast agent and its associated risks. Secondarily, we propose to explore dynamic 4D VFA-FSE acquisitions to produce time-resolved-like MRA images, and assess their accuracy for depicting complex flow patterns in infragenual vessels. PUBLIC HEALTH RELEVANCE: Given the risks and costs associated with gadolinium contrast material, the goal of our proposal is to develop a an accurate, efficient, and robust technique for non-contrast-enhanced peripheral MRA with advantages of obviating exogenous contrast material and reducing costs.

描述（由申请人提供）：下肢外周动脉疾病（PAD）是美国发病率和死亡率的主要原因，在75岁以上的人群中，估计患病率高达20%。钆增强磁共振血管造影（MRA）已成为一种高度准确，微创的方法，已取代DSA在许多诊断设置。最近，钆给药与肾功能不全患者发生肾源性系统性纤维化（NSF）有关。开发不需要钆对比剂的MRA技术对于8 - 38%的PAD肾功能不全患者至关重要。一种有前途的非造影MRA技术，ECG-FSE，使用ECG触发的3D快速自旋回波序列，其利用心动周期期间动脉和静脉血流的差异。根据ECG-FSE的初步经验，我们确定了约50%的时间会影响临床患者图像质量的关键因素：（a）尽管血流特征存在差异，但对双腿应用单组成像参数;（B）相对较长的FSE采集窗口，这会导致图像伪影。在本提案中，我们描述了一种新的方法，VFA-FSE，它结合了一系列的技术改进，包括使用可变翻转角FSE，平行成像，并为每条腿单独的矢状面采集，以克服这些限制。我们的目标是（1）使用脉动流体模和人类受试者系统地开发、测试和改进外周血管3D VFA-FSE MRA，（2）开发和测试动态4D VFA-FSE成像，该成像包含可变触发延迟和可变血流破坏，以改善膝下血管评价;（3）前瞻性测试优化的3站VFA-FSE协议，其中膝下4D VFA-在200例PAD患者中进行FSE，并证明与团注追踪和Gd-MRA以及膝下时间分辨Gd-MRA的准确性相当。我们研究的首要目标是开发和验证一种用于外周MRA的稳健且无伪影的ECG触发可变翻转角FSE技术，该技术可提供解剖结构和疾病的准确诊断，而不会使患者暴露于外源性造影剂及其相关风险。其次，我们建议探索动态4D VFA-FSE采集，以产生时间分辨的MRA图像，并评估其描绘膝下血管复杂血流模式的准确性。公共卫生关系：考虑到钆造影剂的风险和成本，我们的目标是开发一种准确、高效和稳健的非造影增强外周MRA技术，其优点是避免使用外源性造影剂并降低成本。