Advanced MRI Technology in Safety & Intervention

描述(申请人提供)：这笔续期拨款是为了响应BRG PAR-13-1371，用于开发用于活体监测的非侵入性和非破坏性成像方法；新的诊断和医疗设备；以及用于心血管治疗的新的生物工程方法。这项赠款针对的是动脉粥样硬化，在晚期疾病中，动脉粥样硬化的特点是含有脂质、钙化和纤维帽的病变，其破裂是中风、心脏病发作和死亡的主要原因。虽然典型的诊断是通过X射线插管，但X射线不能评估斑块内容物、破裂的易感性或早期的室壁增厚。我们的目标是开发一种新颖、安全、微创、快速、高分辨率的心血管成像方式，使用高场强血管内(IV)磁共振成像(MRI)，以评估和监测疾病，并提供靶向治疗。在即将到期的授权期间，我们创建了新的剂量学工具，用于测试磁共振成像过程中内部设备的安全性。我们从理论和实验上证明，内部探测器的信噪比随MRI场强的平方而增大，至少可达7T(T)。这使得3T时80μm IVMRI和7T时40-50μm能够可视化斑块形态。我们开发了一种新的磁共振内窥镜成像方法，它提供的图像流本质上锁定在探头的视场，最高可达2fr/S。由于μ在40-50μm的分辨率现在可以识别容易破裂的斑块，而且由于在更高的MRI领域也可以对移动脂质进行化学选择性成像，因此通过IVMRI对易受攻击的斑块的关键属性-薄纤维帽和移动脂质含量进行特征描述的可能性现在存在。但技术问题依然存在：我们需要更快的IVMRI，并降低对运动的敏感度。我们需要一种化学选择性IVMRI的方法。我们不知道IVMRI与其他IV模式-IV超声(IVUS)或光学相干断层扫描(OCT)-相比如何。如果我们看到疾病，我们能干预吗？这份重新发布的报告解决了所有这些关键问题。Aim 1使用新的稀疏采样和帧移位方法创建了高速实时、运动不敏感的IVMRI功能。目的2开发40-50μm IV高场磁共振成像和化学选择性脂质成像，以表征斑块的帽和内容。目的3进行IVMRI、OCT和IVUS的体内外对比研究。AIM 4为血管成形术以及细胞和超声消融治疗创建了一个高分辨率IVMRI靶向的介入性平台。该项目在第一笔赠款的进展和新的前期工作的支持下，可以提供重要的新的静脉注射成像和介入工具，以促进对心血管疾病的了解和治疗。

DESCRIPTION (provided by applicant): This renewal grant responds to BRG PAR-13-1371 for the development of noninvasive and nondestructive imaging methods for in vivo monitoring; novel diagnostic and medical devices; and new bioengineering ap- proaches to cardiovascular treatment. The grant targets atherosclerosis, which in advanced disease, is characterized by lesions with lipids, calcification, and fibrous caps whose rupture are a leading cause of stroke, heart attack and death. While typically diagnosed by X-ray catheterization, X-ray can't assess plaque contents, vulnerability to rupture, or early stage wall-thickening. Our goal is to develop a novel, safe, mini- mally-invasive, fast, high-resolution, cardiovascular imaging modality employing high-field intravascular (IV) magnetic resonance imaging (MRI), to assess and monitor disease, and provide targeted therapy delivery. In the expiring grant period we created novel dosimetry tools for testing the safety of internal devices dur- ing MRI. We showed theoretically and experimentally that the signal-to-noise ratio of internal detectors in- creased with MRI field strength-squared, at least up to 7 Tesla (T). This enabled 80μm IVMRI at 3T and 40- 50μm at 7T to visualize plaque morphology. We developed a new μ-imaging method, 'MRI endoscopy' that provides a stream of images intrinsically locked to the probe's viewpoint at up to 2 fr/s. Because IVMRI resolution at 40-50μm is now within a range that could identify plaques vulnerable to rupture, and because chemically-selective imaging of mobile lipids is also possible at higher MRI fields, the possibility of character- izing key attributes of vulnerable plaque-thin fibrous caps and mobile lipid contents by IVMRI, now exists. But technical issues remain: we need still faster IVMRI, and reduced sensitivity to motion. We need a method of chemically selective IVMRI. We don't know how IVMRI compares with other IV modalities-IV ul- trasound (IVUS) or optical coherence tomography (OCT). And if we see disease, can we intervene? This re- newal addresses all these key questions. Aim 1 creates a high-speed real-time, motion-insensitive IVMRI capability using novel sparse sampling and frame-shifting methods. Aim 2 develops high-field 40-50μm IV MRI and chemically-selective lipid imaging to characterize plaque caps and contents. Aim 3 performs com- parative studies in vitro and in vivo of IVMRI, OCT, and IVUS. Aim 4 creates an interventional platform for high-resolution IVMRI-targeting, demonstrated for angioplasty, and cellular and ultrasound ablation thera- pies. This project, supported by progress in the 1st grant and new preliminary work, can provide important new IV imaging and interventional tools to advance understanding and treatment of cardiovascular disease.