Advanced MRI Technology in Safety & Intervention

项目摘要 该更新补助金响应BRG PAR-13-1371，用于开发非侵入性和非破坏性 用于体内监测的成像方法;新型诊断和医疗设备;以及新的生物工程应用， 心血管疾病的治疗。这项拨款的目标是动脉粥样硬化，在晚期疾病中， 以脂质、钙化和纤维帽损伤为特征，纤维帽的破裂是导致 中风心脏病发作和死亡虽然通常通过X射线导管插入术进行诊断，但X射线不能评估斑块 内容物、易破裂或早期壁增厚。我们的目标是开发一种新颖，安全，迷你- 采用高场血管内（IV） 磁共振成像（MRI），以评估和监测疾病，并提供靶向治疗。 在即将到期的赠款期间，我们创造了新的剂量测定工具，用于测试内部设备的安全性， 做核磁共振。我们从理论上和实验上表明，内部探测器的信噪比- 随着MRI场强平方增加，至少高达7特斯拉（T）。这使得在3 T和40- 7 T下50？m，以观察斑块形态。我们开发了一种新的成像方法，“MRI内窥镜”， 以高达2 fr/s的速度提供本质上锁定到探头视点的图像流。因为IVMRI 40-50微米的分辨率现在可以识别容易破裂的斑块， 移动的脂质的化学选择性成像在更高的MRI场也是可能的， 通过IVMRI确定易损斑块的关键属性-薄纤维帽和移动的脂质含量。 但技术问题仍然存在：我们需要更快的IVMRI，并降低对运动的敏感性。我们需要一个 化学选择性IVMRI方法。我们不知道IVMRI与其他IV模式相比如何-IV ul- 超声（IVUS）或光学相干断层扫描（OCT）。如果我们看到疾病，我们能干预吗？这一重新 newal回答了所有这些关键问题。Aim 1创建了一个高速实时，运动不敏感的IVMRI 能力，使用新的稀疏采样和移帧方法。Aim 2开发高场40-50 m IV MRI和化学选择性脂质成像以表征斑块帽和内容物。目标3执行COM- IVMRI、OCT和IVUS的体外和体内对比研究。Aim 4创建了一个介入平台， 高分辨率IVMRI靶向，用于血管成形术，细胞和超声消融治疗， 派这个项目，在第一批赠款和新的初步工作的进展支持，可以提供重要的 新的IV成像和介入工具，以促进对心血管疾病的理解和治疗。

PROJECT SUMMARY 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 80¿m IVMRI at 3T and 40- 50¿m at 7T to visualize plaque morphology. We developed a new ¿-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 40-50¿m 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 40-50¿m 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.