High-Resolution, Motion-corrected 3D Cine MRI of Carotid Plaque

 描述(由申请人提供)： 我们在这个项目中的目标是验证MRI的创新，以改善颈动脉斑块的特征，并最终改善颈动脉疾病的管理。在美国每年近690,000个缺血性中风中，颈动脉粥样硬化性疾病是173,000个或大约25%的直接原因。然而，目前基于狭窄百分比的风险分层对于大多数患有颈动脉疾病的退伍军人来说，提供的关于中风实际风险的患者特定信息非常少。在过去的4年里，在VA系统内，超过15,000名退伍军人接受了无症状颈动脉狭窄的手术治疗。前瞻性随机研究发现，在这些无症状的患者中，只有10%的人会在5年内发生中风，而绝大多数人永远不会发生脑血管事件。虽然颈动脉狭窄百分比是一个公认的标记，用于将患者分成不同的治疗或手术，但这种方法只是中等敏感、非特异性，而且预测未来中风的能力有限。使用可以对斑块表面形态和成分进行成像的MRI技术，前瞻性纵向研究表明，颈动脉炎症、斑块内出血(IPH)和斑块管腔表面破裂(纤维帽破裂(FC))与脑缺血事件的风险增加有关。尽管前景看好，但这些研究的准确性受到重要斑块特征的小尺寸、动脉的深度、患者运动以及所使用的MRI技术的一般限制的限制。在这个项目中，我们将评估新开发的3D MRI采集方法，这些方法是专门设计来改进这些重要斑块细节的检测和表征的。更快的成像与检测和消除运动腐败的方法相结合，将显著提高体内斑块成分的空间分辨率和清晰度。结合高分辨率3D MRI、运动检测和校正，以及心脏和呼吸变异的识别和消除，将以前所未有的分辨率提供斑块形态的详细信息。通过克服颈动脉成像中大多数运动伪影的来源，这项工作将降低颈动脉MRI的失败率，并提高评估纤维帽、斑块内出血和炎症的准确性。吞咽检测和图像重新采集应消除或减少主要的吞咽伪影。通过改善斑块形态的可视化和描述，这些方法应该可以改善对高风险导致脑血栓的病变的检测和表征。有效地对颈动脉疾病进行分诊的能力将是显著的好处，为 那些没有高危病变的患者可以安全地接受治疗，而不需要手术，同时为那些有不稳定斑块的患者进行干预的建议提供了实质性的支持。

 DESCRIPTION (provided by applicant): Our goal in this project is to validate innovations in MRI to improve the characterization of carotid plaque and ultimately improve the management of carotid disease. Atherosclerotic disease of the carotid artery is the direct cause of 173,000 or approximately 25% of the nearly 690,000 ischemic strokes each year in the United States. However, current risk stratification based on percent stenosis provides very little patient specific information on the actual risk of stroke for most veterans with carotid disease. Within the VA system during the past 4-years, over 15,000 veterans underwent surgical treatment for asymptomatic carotid stenosis. Prospective randomized studies have found that only 10% of these asymptomatic patients will have a stroke within 5 years, and the significant majority will never have a cerebrovascular event. Although percent carotid stenosis is a well-established marker used to stratify patients to medical treatment or surgery, this method is only moderately sensitive, nonspecific, and limited in its ability to predict future stroke. Using MRI techniques that can image plaque surface morphology and composition, prospective longitudinal studies suggest that carotid inflammation, intraplaque hemorrhage (IPH) and plaque luminal surface disruption (disruption of fibrous cap (FC)) are associated with an increased risk of cerebral ischemic events. Although promising, the accuracy of these studies is limited by the small size of important plaque features, the depth of the artery, patient motion, and the general limitations of the MRI techniques used. In this project we will evaluate newly developed 3D MRI acquisition methods that are specifically designed to improve the detection and characterization of these important plaque details. Faster imaging coupled with methods to detect and eliminate motion-corruption will achieve a marked increase in in-vivo spatial resolution and clarity of plaque components. The combination of high-resolution 3D MRI, motion detection and correction, and cardiac and respiratory variation identification and elimination will provide detail of plaque morphology at a resolution not previously available. By overcoming most sources of motion artifacts in carotid imaging, this work will reduce the failure rate of carotid MRI and increase the accuracy in assessment of fibrous cap, intraplaque hemorrhage, and inflammation. The swallow detection and image re-acquisition should eliminate or reduce major swallowing artifacts. By improving the visualization and description of plaque morphology, these methods should improve the detection and characterization of lesions that are at high risk of causing cerebral emboli. The ability to effectively triage carotid artery disease would be of significant benefit, providing reassurance to those without high-risk lesions that they can safely be treated without surgery while providing substantial support to the recommendation for intervention in those with unstable plaques.