Direct Measurements of Microstructure from MRI

通过 MRI 直接测量微观结构

• 批准号: EP/G007748/1
• 负责人: Daniel Alexander
• 金额: $ 204.94万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FG007748%2F1
• 关键词: Direct; Measurements; Microstructure; MRI

The research will produce a new imaging paradigm called active imaging . Traditional imaging techniques are designed by physicists; medical or biological researchers use them if they provide useful contrast between different types of material or correlate with interesting effects. Recent trends in medical imaging are towards quantitative imaging techniques that combine biophysical models of tissue with traditional imaging techniques to provide more specific information relevant to particular applications. Active imaging extends this idea to exploit biophysical models more completely to design the imaging techniques themselves. More specifically, the technique uses optimization algorithms to search for combinations of images that provide the most information about the biophysical model and the best estimates of biologically relevant quantities.For example, Alzheimer's diseaseattacks and destroys brain cells. It leaves holes in brain tissue and deposits of unusual proteins. Brain tissue from Alzheimer's patients looks very different to normal tissue under a microscope, but the differences are not apparent on images from standard techniques like magnetic resonance imaging (MRI). Even techniques like diffusion-tensor MRI, which has acute sensitivity to tissue microstructure, show only moderate contrast. A broader class of technique, called diffusion MRI, measures the scattering of water molecules in tissue. The tissue microstructure controls the scatter pattern and so diffusion MRI provides information about the microstructure. Diffusion-tensor MRI provides only particular features of the scatter pattern that happen to be insensitive to the microstructural changes in Alzheimer's. However, we can tune the sensitivity of diffusion MRI in an almost infinite number of other ways. Active imaging will use a model of the microstructural changes in Alzheimer's to find the precise combination of diffusion MRI measurements that is most sensitive to those changes and discriminates them most successfully from normal tissue or other diseases.The project considers three diseases: Alzheimer's, multiple sclerosis and focal cortical dyplasia (a common cause of epilepsy). Each has characteristic abnormalities in brain tissue microstructure that current imaging techniques do not reveal reliably. The project will construct biophysical models of the abnormalities and use active imaging to devise diffusion MRI techniques that reveal them. The project will also use active imaging to tune diffusion MRI to reveal specific microstructural features of normal brain tissue, such as size and density of axons in white matter. No current technique can image these features in live subjects, but the information would provide fundamental new information about the structure and function of the brain. The active-imaging paradigm extends to almost any other imaging technique including other MRI techniques, X-ray or optical tomography or positron-emission tomography (PET). Although the project focusses on active imaging for diffusion MRI, it also aims to initiate follow-on projects to explore applications to other diseases (such as cancers) and other imaging techniques.

这项研究将产生一种新的成像模式，称为主动成像。传统的成像技术是由物理学家设计的;医学或生物学研究人员使用它们，如果它们在不同类型的材料之间提供有用的对比或与有趣的效果相关。医学成像的最近趋势是朝向定量成像技术，其将组织的生物物理模型与传统成像技术相结合，以提供与特定应用相关的更具体的信息。主动成像扩展了这一想法，更完全地利用生物物理模型来设计成像技术本身。更具体地说，该技术使用优化算法来搜索图像的组合，这些图像提供了关于生物物理模型的最多信息和生物相关量的最佳估计。它会在脑组织中留下洞并沉积不寻常的蛋白质。阿尔茨海默氏症患者的脑组织在显微镜下看起来与正常组织非常不同，但在磁共振成像（MRI）等标准技术的图像上，这种差异并不明显。即使像弥散张量MRI这样对组织微观结构具有急性敏感性的技术，也只能显示中等的对比度。一种更广泛的技术，称为扩散MRI，测量水分子在组织中的散射。组织微结构控制散射模式，因此扩散MRI提供了关于微结构的信息。扩散张量MRI仅提供散射模式的特定特征，这些特征恰好对阿尔茨海默氏症的微观结构变化不敏感。然而，我们可以通过几乎无数种其他方式来调整弥散MRI的灵敏度。主动成像将使用阿尔茨海默氏症的微观结构变化模型来找到对这些变化最敏感的弥散MRI测量的精确组合，并最成功地将它们与正常组织或其他疾病区分开来。该项目考虑了三种疾病：阿尔茨海默氏症，多发性硬化症和局灶性皮质发育不良（癫痫的常见原因）。每一种都有脑组织微观结构的特征性异常，而目前的成像技术无法可靠地揭示这些异常。该项目将构建异常的生物物理模型，并使用主动成像来设计揭示它们的扩散MRI技术。该项目还将使用主动成像来调整扩散MRI，以揭示正常脑组织的特定微观结构特征，例如白色物质中轴突的大小和密度。目前还没有技术可以在活体上成像这些特征，但这些信息将提供有关大脑结构和功能的基本新信息。主动成像范例扩展到几乎任何其他成像技术，包括其他MRI技术、X射线或光学断层扫描或正电子发射断层扫描（PET）。虽然该项目的重点是扩散MRI的主动成像，但它也旨在启动后续项目，以探索其他疾病（如癌症）和其他成像技术的应用。

项目成果

Susceptibility-induced distortion that varies due to motion: Correction in diffusion MR without acquiring additional data.

• DOI: 10.1016/j.neuroimage.2017.12.040
• 发表时间: 2018-05-01
• 期刊: NeuroImage
• 影响因子: 5.7
• 作者: Andersson JLR;Graham MS;Drobnjak I;Zhang H;Campbell J
• 通讯作者: Campbell J

Image processing and Quality Control for the first 10,000 brain imaging datasets from UK Biobank.

• DOI: 10.1016/j.neuroimage.2017.10.034
• 发表时间: 2018-02-01
• 期刊: NeuroImage
• 影响因子: 5.7
• 作者: Alfaro-Almagro F;Jenkinson M;Bangerter NK;Andersson JLR;Griffanti L;Douaud G;Sotiropoulos SN;Jbabdi S;Hernandez-Fernandez M;Vallee E;Vidaurre D;Webster M;McCarthy P;Rorden C;Daducci A;Alexander DC;Zhang H;Dragonu I;Matthews PM;Miller KL;Smith SM
• 通讯作者: Smith SM

Towards a comprehensive framework for movement and distortion correction of diffusion MR images: Within volume movement.

• DOI: 10.1016/j.neuroimage.2017.02.085
• 发表时间: 2017-05-15
• 期刊: NeuroImage
• 影响因子: 5.7
• 作者: Andersson JLR;Graham MS;Drobnjak I;Zhang H;Filippini N;Bastiani M
• 通讯作者: Bastiani M

Microstructure models for diffusion MRI in breast cancer and surrounding stroma: an ex vivo study

乳腺癌及其周围基质的扩散 MRI 微观结构模型：一项离体研究

• 发表时间: 2016
• 作者: Bailey CEM