Pediatric Template of Brain Perfusion

描述(由申请人提供)：项目摘要/摘要建议项目的主题是基于使用动脉自旋标记(ASL)灌注磁共振成像(MRI)的定量脑血流(CBF)测量来开发发育中脑的功能模板或图谱。脑实质血流灌注是评价和治疗脑部疾病的重要生理参数，也是神经活动的替代指标。由于现有的依靠放射性同位素和造影剂测量血流灌注的方法存在安全问题和技术困难，此类信息在儿科人群中一直很稀少。ASL灌注MRI非常适合于儿童脑灌注成像，因为它是完全非侵入性的，并且由于儿童大脑的独特生理特性而提供高图像质量。对于追踪神经发育变化的纵向研究来说，绝对CBF量化能力是ASL的另一个可取特征。通过NIMH资助的人脑项目(R21-MH072576，Pi：Wang)，我们已经建立了使用ASL的儿童脑灌注MRI的可行性，并展示了健康儿童的脑血流发育轨迹以及临床前和临床儿童人群的脑血流灌注异常。建议的R01项目代表了一项持续和系统的努力，以利用ASL灌注MRI解决儿童大脑的功能发育问题。我们将首先建立测试-再测试的可重复性，并确定构建儿科灌注模板的最佳ASL技术和成像参数。儿童ASL CBF测量的准确性将通过相位对比MRI技术确定的到脑的整体血流速度来验证。在接下来的4年里，我们将基于基线的ASL血流灌注测量，制定7-16岁健康儿童脑血流灌注的标准发育模板。在最后一个目标中，我们将使用并行的ASL和BOLD(血氧水平依赖)fMRI范式来表征CBF的定量变化，以响应一个特征良好的认知范式-工作记忆任务。一旦研制成功，儿童脑灌注模板不仅将阐明脑功能随年龄的演变，还将为未来的发育神经科学研究以及儿童脑疾病的临床研究提供有价值的资源和参考系统。公共卫生相关性：拟议的项目将开发7-16岁健康儿童脑血流(灌注)的功能模板或图谱。一种名为动脉自旋标记的非侵入性磁共振成像技术将用于以高精度和空间分辨率测量儿童大脑的血流灌注。开发的儿童脑灌注模板不仅将阐明脑功能随年龄的演变，而且将为未来儿童脑疾病的临床和认知神经科学研究提供有价值的资源和参考系统。

DESCRIPTION (provided by applicant): Project Summary/Abstract The theme of the proposed project is to develop a functional template or atlas of the developing brain based on quantitative cerebral blood flow (CBF) measurements using arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI). Parenchymal perfusion is an important physiologic parameter in the evaluation and management of brain disorders as well as a surrogate index of neural activity. Such information has been sparse in the pediatric population due to the safety concerns and technical difficulties associated with existing methods to measure perfusion that rely on radioisotopes and contrast agents. ASL perfusion MRI is ideally suited for pediatric perfusion imaging, because it is totally noninvasive and provides high image quality due to unique physiologic properties of a child brain. The capability for absolute CBF quantification is another desirable feature of ASL for longitudinal studies to follow neurodevelopmental changes. Through a pilot Human Brain Project funded by NIMH (R21- MH072576, PI: Wang), we have established the feasibility of pediatric perfusion MRI using ASL, and demonstrated the developmental trajectory of CBF in healthy children as well as perfusion aberrations in pre-clinical and clinical pediatric populations. The proposed R01 project represents a continued and systematic effort to address the functional development of a child brain utilizing ASL perfusion MRI. We will first establish the test-retest repeatability and determine the optimal ASL technique along with imaging parameters for constructing the pediatric perfusion template. The accuracy of ASL CBF measurement in children will be validated using global flow rate to the brain determined by phase contrast MRI technique. In the following 4 years, we will develop the normative developmental template of brain perfusion in healthy children aged 7-16 based on ASL perfusion measurements at baseline. In the last aim, we will characterize the quantitative CBF changes in response to a well-characterized cognitive paradigm - working memory tasks - using a concurrent ASL and BOLD (blood-oxygen-level- dependent) fMRI paradigm. Once developed, the pediatric perfusion template will not only shed light on the evolution of brain function with age, but will also provide a valuable resource and reference system for future developmental neuroscience studies as well as clinical studies on childhood brain disorders. PUBLIC HEALTH RELEVANCE: The proposed project will develop a functional template or atlas of the cerebral blood flow (perfusion) in healthy children aged 7-16 years. A noninvasive magnetic resonance imaging technique termed arterial spin labeling will be used to measure perfusion of a child brain with high precision and spatial resolution. The developed pediatric perfusion template will not only shed light on the evolution of brain function with age, but will also provide a valuable resource and reference system for future clinical and cognitive neuroscience studies on childhood brain disorders.