Diffusion tensor MR spectroscopic imaging in human brain

人脑扩散张量磁共振波谱成像

• 批准号: 8112342
• 负责人: Stefan Posse
• 金额: $ 18.52万
• 依托单位: UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8112342
• 关键词: 3 year old; Adult; Anisotropy; Area; Autistic Disorder; Brain; Cells; Cerebrum; Child; Choline; Clinical; Clinical Research; Corpus Callosum; Creatine; Cytoplasmic streaming; Data; Development; Developmental Process; Diffusion; Diffusion Magnetic Resonance Imaging; Disease Progression; Exhibits; Goals; Heterogeneity; Human; Image; Imaging Techniques; Inflammatory; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Maps; Measures; Methodology; Methods; Motion; Movement; Muscle; Nursery Schools; Organ; Phase; Process; Property; Protons; Publishing; Relaxation; Research; Resolution; Specificity; Spectrum Analysis; Speed; Staging; Subcellular structure; Swelling; Techniques; Testing; Time; Tissues; Viscosity; Water; Width; Work; aged; autism spectrum disorder; base; diffusion anisotropy; extracellular; frontal lobe; image reconstruction; imaging modality; millimeter; motion sensitivity; nervous system disorder; novel; reconstruction; regional difference; spectroscopic imaging; theories; water diffusion; white matter

DESCRIPTION (provided by applicant): Diffusion tensor imaging (DTI) characterization of white matter microstructure abnormalities in autism spectrum disorder (ASD) generally demonstrate decreased water diffusion anisotropy in frontal cortex and corpus callosum, consistent with frontal disconnectivity theories of autism. However, DTI findings in ASD show considerable heterogeneity and little is known about differential involvement of the intracellular and extracellular compartments or mechanisms underlying changes in water diffusion that limit the extent to which DTI can be used to characterize developmental processes in ASD. Diffusion tensor 1H MRSI (DTSI) can provide unique information on intracellular properties, such as viscosity, cell swelling, restriction in subcellular structures and cytoplasmic streaming, that may help to characterize possible inflammatory processes in autism. All human studies so far have used single voxel localization method (e.g. Posse et al 1993a, Ellegood et al 2005 and 2006, Upadhyay et al 2007) due to overwhelming motion sensitivity of conventional MRSI techniques (Posse et al. 1993b), which do not allow mapping of metabolite diffusion across extended brain areas hypothesized to be involved in autism. The objective of this proposal is to develop single-shot diffusion sensitive MRSI to dramatically reduce motion sensitivity, and to show feasibility of volumetric mapping of metabolite diffusion in healthy adults and children with ASD using a clinical 3 Tesla whole body scanner. The specific aims of this proposal are: 1. to develop DTSI with single-shot 2D spatial-spectral encoding and correction for macroscopic movement using (a) compressed sensing combined with parallel imaging and (b) SURE-SENSE reconstruction to further increase spatial resolution. An exploratory aim is to investigate feasibility of single-shot 3D spatial- spectral encoding using 2D compressed sensing combined with parallel imaging. 2. To validate DTSI in phantoms and healthy adult brain at 3 T The working hypothesis is that single-shot DTSI can map the diffusion tensors of tissue water, Choline, Creatine and NAA with sensitivity per unit time and unit volume that is comparable to single-voxel diffusion tensor spectroscopy. 3. To demonstrate feasibility of DTSI in the brains of 3 year old children with ASD at 3 T The working hypothesis is that DTSI will detect regional decreases in diffusion anisotropy of NAA in ASD. An exploratory aim is to determine whether NAA diffusion anisotropy in these regions will be more strongly decreased in comparison to diffusion anisotropy of tissue water measured with DTSI and DTI, implicating intracellular inflammatory processes. This DTSI methodology has the potential to enhance the scope of imaging studies of ASD by helping to clarify mechanisms underlying abnormal brain development in ASD through characterizing the involvement of intracellular compartments and in relationship to the time course of disease progression. Applications to other organs and muscle are also foreseeable. PUBLIC HEALTH RELEVANCE: The objective of this research is to develop a novel ultra high-speed MR spectroscopic imaging technique for mapping the diffusion tensors of brain metabolites using a 3 Tesla whole body MRI scanner. The goal of this research is to enhance the specificity of the widely used diffusion tensor imaging (DTI) method for clinical studies of neurological diseases by measuring metabolite mobility in the intracellular compartments and to relate this measure to the time course of disease progression. The specific aims of this application are (a) Develop single-shot diffusion sensitive 1H MR spectroscopic imaging using a combination of compressed sensing and parallel imaging reconstruction at 3 T, (b) validate this methodology in human brain at 3 T, and (c) demonstrate the feasibility of DTSI in the brains of 3 year old children with Autism Spectrum Disorder at 3 T. This DTSI methodology has the potential to enhance the scope of imaging studies of ASD by helping to clarify mechanisms underlying abnormal brain development in ASD through characterizing the involvement of intracellular compartments and in relationship to the time course of disease progression. Applications to other organs and muscle are also foreseeable.

描述（由申请人提供）：自闭症谱系障碍（ASD）中白色物质微结构异常的扩散张量成像（DTI）表征通常表明额叶皮质和胼胝体中的水扩散各向异性降低，与自闭症的额叶断开理论一致。然而，在ASD的DTI研究结果显示相当大的异质性和知之甚少的差异参与的细胞内和细胞外的隔间或水扩散的变化，限制了DTI可以用来表征ASD的发育过程的程度的机制。 扩散张量1H MRSI（DTSI）可以提供关于细胞内特性的独特信息，例如粘度，细胞肿胀，亚细胞结构和细胞质流动的限制，这可能有助于表征自闭症中可能的炎症过程。由于传统MRSI技术（波塞等人，1993 b）的运动灵敏度过高，因此迄今为止所有人体研究均使用了单体素定位方法（例如，波塞等人，1993 a; Ellegood等人，2005和2006; Upadhyay等人，2007），无法对假设与自闭症相关的扩展脑区的代谢物扩散进行标测。 本提案的目的是开发单次激发扩散敏感MRSI，以显著降低运动敏感性，并显示使用临床3特斯拉全身扫描仪在健康成人和ASD儿童中进行代谢物扩散体积标测的可行性。该提案的具体目标是：1.开发具有单次激发2D空间-频谱编码和宏观运动校正的DTSI，使用（a）压缩传感结合并行成像和（B）SURE-SENSE重建以进一步提高空间分辨率。探索性的目的是研究使用2D压缩感知结合并行成像的单次激发3D空间频谱编码的可行性。 2.为了在3 T下验证幻影和健康成人大脑中的DTSI，工作假设是单次激发DTSI可以映射组织水、胆碱、肌酸和NAA的扩散张量，其每单位时间和单位体积的灵敏度与单体素扩散张量光谱学相当。 3.为了证明DTSI在3岁ASD儿童的大脑中在3 T下的可行性，工作假设是DTSI将检测ASD中NAA的扩散各向异性的局部降低。一个探索性的目的是，以确定是否NAA扩散各向异性在这些地区将更强烈地降低相比，用DTSI和DTI测量的组织水的扩散各向异性，牵连细胞内炎症过程。 这种DTSI方法有可能通过表征细胞内室的参与以及与疾病进展的时间过程的关系来帮助澄清ASD中异常脑发育的潜在机制，从而增强ASD的成像研究范围。也可以预见应用于其他器官和肌肉。 公共卫生关系：本研究的目的是开发一种新的超高速磁共振波谱成像技术，用于使用3特斯拉全身MRI扫描仪绘制脑代谢物的扩散张量。本研究的目的是通过测量细胞内室中代谢物的迁移率来增强广泛使用的弥散张量成像（DTI）方法在神经系统疾病临床研究中的特异性，并将该测量与疾病进展的时间过程联系起来。 本申请的具体目的是（a）在3 T下使用压缩感知和并行成像重建的组合开发单次激发扩散敏感1H MR光谱成像，（B）在3 T下在人脑中验证该方法，以及（c）在3 T下证明DTSI在患有自闭症谱系障碍的3岁儿童大脑中的可行性。 这种DTSI方法有可能通过表征细胞内室的参与以及与疾病进展的时间过程的关系来帮助澄清ASD中异常脑发育的潜在机制，从而增强ASD的成像研究范围。也可以预见应用于其他器官和肌肉。