Flow Sensitive SSFP for Non-Contrast MRA and Vessel Wall Imaging

描述（由申请人提供）：该提案的广泛、长期目标是改善动脉疾病患者的预后，动脉疾病是美国的主要原因之一。对比增强成像是临床上公认的MRA常规方法。然而，接受钆基药物的肾功能不全患者有患上肾源性系统性纤维化的使人衰弱且可能致命的疾病的风险。拟议项目的目的是开发一种新的非增强 MRA 技术。将分别在有或没有血流敏化相移 (FSD) 准备的情况下采集两组心电图触发的心脏相位分辨 3D 图像。在收缩期，稳态自由进动 (SSFP) 成像会为动脉和静脉产生明亮的血液信号，与血流无关，而使用 FSD 准备获取的图像显示黑色的血液动脉和明亮的血液静脉，因为 FSD 准备会对快速流动的动脉血液造成显着的信号损失，但对缓慢流动的静脉血液和背景组织影响很小。两个图像集相减将仅显示动脉。 “黑血”图像还可用于动脉壁评估，以量化斑块负荷。因此，该技术具有同时进行全身 MRA 和动脉壁成像的潜力。该项目的具体目标是： (1) 开发心脏相位分辨、FSD 准备、自门控 3D SSFP 技术，用于同步 MRA 和动脉壁成像。将执行四项任务：（a）将开发一种自门控方法，以消除由于运动（例如，颈动脉 MRA 期间的吞咽和肾 MRA 的呼吸运动）造成的潜在图像伪影。 (b) SSFP 将得到改善，以在存在流动的情况下实现一致的亮血 MRA。 (c) 将优化 FSD 准备和数据采集方案，以最大限度地提高颈动脉、肾和外周动脉 MRA 和血管壁成像的动脉血和背景/静脉之间的对比度噪声比。 (d) 将优化 k-t 并行成像，以提高心脏相位分辨 MRA 和血管壁成像的速度。 (2)验证非造影MRA和血管壁成像技术能够准确描绘动脉狭窄并量化患者的斑块负荷。将研究三组​​分别患有颈动脉、肾和外周动脉疾病的患者。对比增强 MRA 和单层涡轮自旋回波技术将分别用作 MRA 和壁成像的参考方法。该项目的终点是开发一种新的非对比增强 MRA 方法并进行初步临床验证，该方法能够同时对全身进行 MRA 和动脉壁成像。公共健康相关性：该项目的总体目标是开发一种非增强磁共振成像技术来检测肾功能不全患者的动脉疾病。

DESCRIPTION (provided by applicant): The broad, long-term objective of this proposal is to improve the prognosis of patients with arterial disease, one of the leading causes of death in the United States. Contrast-enhanced imaging is the clinically accepted conventional method for MRA. However, patients with renal insufficiency who receive gadolinium- based agents are at risk for developing a debilitating and a potentially fatal disease known as nephrogenic systemic fibrosis. The purpose of the proposed project is to develop a new non-contrast-enhanced MRA technique. Two sets of ECG-triggered, cardiac phase-resolved 3D images will be acquired with and without flow sensitized dephasing (FSD) preparation, respectively. In systole, steady state free precession (SSFP) imaging generates bright blood signals for both arteries and veins, independent of flow, while images acquired with FSD preparation show black blood arteries and bright blood veins because FSD preparation causes dramatic signal loss to fast flowing arterial blood but has little effect on slow flowing venous blood and background tissue. Subtraction of the two image sets will show arteries only. The "black-blood" images can also be used for arterial wall evaluation to quantify plaque burden. Therefore, this technique has the potential for simultaneous MRA and arterial wall imaging of the entire body. Specific aims of the project are: (1) To develop the cardiac phase-resolved, FSD-prepared, self-gated 3D SSFP technique for simultaneous MRA and arterial wall imaging. Four tasks will be performed: (a) A self-gating method will be developed to eliminate potential image artifacts due to motion (e.g., swallowing during carotid MRA and respiratory motion for renal MRA). (b) SSFP will be improved for consistent bright blood MRA in the presence of flow. (c) FSD preparation and data acquisition schemes will be optimized to maximize contrast to noise ratio between arterial blood and background/vein for MRA and vessel wall imaging in carotid, renal, and peripheral arteries. (d) k-t parallel imaging will be optimized to improve the speed of cardiac phase-resolved MRA and vessel wall imaging. (2) To verify that the non-contrast MRA and vessel wall imaging technique can accurately depict artery stenoses and quantify plaque burden in patients. Three groups of patients with carotid, renal, and peripheral artery disease, respectively, will be studied. Contrast-enhanced MRA and single-slice turbo spin echo techniques will be used as the reference methods for MRA and wall imaging, respectively. The end point of the project is the development and initial clinical validation of a new non-contrast- enhanced MRA approach capable of simultaneous MRA and arterial wall imaging of the entire body. PUBLIC HEALTH RELEVANCE: The overall objective of this project is to develop a non-contrast-enhanced magnetic resonance imaging technique to detect artery disease in patients with renal insufficiency.