MRI Study of Normal Brain Development

许多障碍阻碍了对儿童大脑疾病的神经成像研究。这些问题包括：由于儿童遵守程序的能力有限，很难从他们那里获得数据；缺乏足够的标准数据库来描述正常的大脑发育并对照其来确定和衡量异常的大脑发育；缺乏适当的图像分析工具来描述发育性大脑的变化；以及缺乏共享数据分析工具的适当手段。 四家NIH研究所(NICHD、NIMH、NINDS和NIDA)联合发起了一项多中心研究，以促进我们对典型的健康儿童和青少年大脑发育的了解。这项研究招募了大约500名儿童，从婴儿期到成年期，他们在六年的时间里在美国各地的几个临床中心被观察到不同的时间点。正在进行大脑的磁共振成像(MRI)，成像结果与标准化的神经心理测试结果相关。 该项目有几个目的：(1)促进对正常人脑发育的研究；(2)为患有脑障碍和疾病的儿童的研究提供必要的、有代表性的和可靠的正常对照数据来源；(3)为正常的大脑解剖提供生长曲线；以及(4)帮助开发儿科神经成像工具。有关该项目的更多信息，请访问：“正常大脑发育的核磁共振研究”网站：http://www.brain-child.org/. 我们的角色是作为扩散张量数据处理中心(DPC)。这需要处理和分析在研究过程中由各个中心获取的所有扩散张量磁共振(DT-MRI)数据。 此前，我们一直在开发和实施DT-MRI数据处理“流水线”。具体地说，我们开发了用于分类、显示和共同配准扩散加权图像的程序，从这些图像中可以获得DT-MRI数据。图像配准过程完成了去除被摄体运动和涡流失真的影响以及仅用一个内插步骤将图像与给定模板对齐的任务，确保了最小的数据质量损失。我们还提出了一种新的策略来稳健估计扩散张量及其派生的量。我们解决了使用刚体变换将DT-MRI数据与数据库中包含的其他结构MRI数据配准的任务，并计划在不久的将来使用非线性变形程序。 2005年，该项目获得了神经科学蓝图基金，以扩大该研究的DTI部分。最初的DTI数据收集仅限于在收集核心结构MRI数据后对那些能够在扫描仪中忍受额外时间的受试者执行的10分钟方案。这一扩展将提高通过较长时间或额外扫描较老对象收集的数据的质量和数量，并为较年轻的人群增加新对象和扫描对象。我们小组正在设计扩展的DTI协议，并协调其在每个采购点的实施。

Many obstacles have impeded neuroimaging research on childhood brain disorders. These include difficulties in obtaining data from children given their limited ability to comply with procedures, the lack of an adequate normative data base with which to characterize normal brain development and against which to identify and measure aberrant brain development, the lack of adequate image analysis tools for characterizing developmental brain changes, and a lack of an adequate means for sharing data analytic tools. Four NIH Institutes (NICHD, NIMH, NINDS, and NIDA) have jointly sponsored a multi-center study to advance our understanding about how the brain develops in typical, healthy children and adolescents. This study is enrolling approximately 500 children, ranging from infancy to young adulthood, who are being seen at different time points over a six-year period at several clinical centers around the US. Magnetic Resonance Images (MRI) of the brain are being performed and the imaging findings are being related to the results of standardized neuropsycological tests. This project serves several purposes: (1) to facilitate the study of normal human brain development; (2) to provide a necessary, representative, and reliable source of normal control data for studies of children with brain disorders and diseases; (3) to provide growth curves for normal brain anatomy; and (4) to aid in the development of pediatric neuroimaging tools. More information regarding this project can be found at the: "MRI Study of Normal Brain Development" website: http://www.brain-child.org/. Our role is to serve as a Diffusion Tensor Data Processing Center (DPC). This entails processing and analyzing all diffusion tensor MRI (DT-MRI) data that is being acquired by the various Centers during the course of the study. Previously, we have been developing and implementing the DT-MRI data processing "pipeline". Specifically we developed procedures for sorting, displaying, and co-registering diffusion weighted images from which the DT-MRI data is obtained. The image registration procedure accomplishes the tasks of removing the effects of subject motion and eddy current distortion as well as aligning the images to a given template with only one interpolation step, ensuring minimal data quality loss. We also proposed a new strategy for robust estimation of the diffusion tensor and quantities derived from it. We addressed the task of registering DT-MRI data to other structural MRI data contained in the database using rigid body transformations and we plan to use non-linear deformation procedures in the near future. In 2005 the project was awarded Neuroscience Blueprint funds to expand the DTI portion of the study. The original DTI data collection was limited to a 10-minute protocol performed on those subjects able to tolerate additional time in the scanner following the collection of the core structural MRI data. This expansion will increase the quality and amount of data collected through a longer or an additional scanning session for older subjects, and the addition of new subjects and scanning sessions for the younger cohort. Our group is designing the expanded DTI protocol and coordinating its implementation at each acquisition site.