Rapid high order diffusion imaging for stroke

描述(由申请人提供)：新的计算工具对于利用计算技术的进步影响核磁共振生物医学成像至关重要。这项工作旨在开发、评估和应用用于高端扩散成像的新的MRI方法。这些高角度分辨率的方法适用于扩散张量成像(DTI)方法失败的地方--交叉或接触纤维，这与大脑的太多部位相对应。这对于评估中风后脑白质束的完整性有特别的价值。两项小型研究表明，先进的“后DTI”方法可以提供有价值的信息，预测中风的恢复程度。然而，后DTI方法需要不切实际的扫描持续时间。因此，本项目的目标是：(1)开发用于快速(k和q空间欠采样)扩散测量的先进采集和重建方法。(2)研究先进弥散成像的快速采集和重建方法。(3)测定卒中患者在接受神经源性药物西地那非治疗时，脑白质束完整性随时间的变化。这将允许 以确定高角分辨率后DTI方法的预测能力，并深入了解药物治疗后的变化。这些目标将通过开发软件工具来实现，以提供短时间、临床实用的采集时间的DTI后类型数据。将开发和测试先进的重建方法，包括具有强度重新排序的低阶和时空约束、基于词典的方法和参数模型，以在短时间帧内获得扩散信息。将评估白质束的完整性，并将相对于全长扫描采集确定新方法的重复性和准确性。将这些方法系列应用于接受标准治疗和新型药物治疗的中风患者，将提供与神经元重塑相关的变化的新信息，并可能区分有反应者和无反应者。所产生的软件工具将被纳入洞察工具包，并提供给研究界使用。与公共卫生相关的是，中风是导致残疾的主要原因。准确和可重复的扩散测量的开发和使用将加速临床治疗的评估。该项目还将为更好地管理中风患者提供新的工具和知识。所提出的方法可以扩展到改进广泛的多图像MRI应用，例如肿瘤对治疗的响应和大脑对刺激的响应。

DESCRIPTION (provided by applicant): New computational tools are critical to leverage progress in computational technologies to impact biomedical imaging with MRI. This work seeks to develop, evaluate and apply new MRI methods for high-end diffusion imaging. These high angular resolution methods work where diffusion tensor imaging (DTI) methods fail - in crossing or touching fibers, which corresponds too much of the brain. This is of particular value for assessing white matter tract integrity after stroke. Two small studies have shown that advanced "post-DTI" methods can give valuable information predicting the degree of recovery from stroke. However, the post-DTI methods require impractical scan duration. Thus this project aims to (1) develop advanced acquisition and reconstruction methods for rapid (undersampled in k- and q-space) diffusion measurements. (2) To characterize rapid acquisition and reconstruction methods for advanced diffusion imaging. (3) To determine white matter tract integrity changes over time when patients with stroke are treated with a neurogenic drug, sildenafil. This will allow for determining the predictive power of the high angular resolution post-DTI methods and give insight into changes in response to the drug therapy. These aims will be accomplished by developing software tools to provide post-DTI type data from short, clinically practical, acquisition times. Advanced reconstruction methods that include low rank and spatiotemporal constraints with intensity reordering, dictionary-based approaches, and parametric models will be developed and tested to obtain diffusion information in short time frames. The integrity of the white matter tracts will be estimated and the repeatability and accuracy of the new methods will be determined relative to full long scan acquisitions. The serial application of the methods to patients with stroke undergoing standard therapy and novel drug therapy will then provide new information regarding changes associated with neuronal remodeling and possibly differentiate responders from non-responders. The resulting software tools will be integrated into the insight toolkit (ITK) and provided for use to the research community. The relevance to public health is that stroke is a leading cause of disability. The development and use of accurate and repeatable measurements of diffusion will accelerate evaluation of clinical therapies. The project will also provide new tools and knowledge for better management of patients with stroke. The proposed approach can be extended to improve a wide range of multi-image MRI applications, such as the response of tumors to therapy and the response of the brain to stimuli.