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

描述(由申请人提供)：这项提案的广泛、长期目标是改善动脉疾病患者的预后，动脉疾病是美国主要的死亡原因之一。对比度增强成像是临床公认的常规MRA方法。然而，肾功能不全的患者在接受基于Gd的药物治疗后，有患上一种虚弱的潜在致命疾病的风险，这种疾病被称为肾源性系统性纤维化。该项目的目的是开发一种新的非对比增强磁共振血管成像技术。将分别在有和没有血流敏化消相(FSD)准备的情况下采集两套由心电触发的心脏相分辨3D图像。在收缩期，稳态自由进动(SSFP)成像产生动脉和静脉的明亮血流信号，与血流无关，而FSD准备获得的图像显示黑色的动脉和明亮的血管，因为FSD准备对快速流动的动脉血液造成显著的信号损失，但对缓慢流动的静脉血液和背景组织影响不大。减去这两个图像集将只显示动脉。“黑血”图像也可用于动脉壁评估，以量化斑块负荷。因此，这项技术有可能同时进行MRA和全身动脉壁成像。该项目的具体目标是：(1)开发心脏相分辨、FSD制备、自门3D SSFP技术，用于同时进行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，以消除运动(例如，颈动脉MRA中的吞咽和肾脏MRA中的呼吸运动)可能导致的图像伪影。(B)在有血流存在的情况下，SSFP将得到改善，以获得一致的明亮血液MRA。(C)将优化消防处的准备和数据采集计划，以最大限度地提高动脉血液和背景/静脉之间的对比度，以进行颈动脉、肾动脉和外周动脉的MRA和血管壁成像。(D)将优化k-t平行成像，以提高心脏相分辨MRA和血管壁成像的速度。(2)验证非对比MRA和管壁成像技术能准确显示患者的动脉狭窄和斑块负荷。将对三组分别患有颈动脉、肾脏和外周动脉疾病的患者进行研究。对比度增强的MRA和单层快速自旋回波技术将分别用作MRA和WALL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，该方法能够同时进行全身MRA和动脉壁成像。公共卫生相关性：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.