FUNCTIONAL DIFFUSE OPTICAL TOMOGRAPHY OF THE BRAIN

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 近红外光谱（NIRS）是一种非侵入性，非电离，和廉价的 使用近红外光探测组织光学的监测和成像技术 特性. 氧合血红蛋白和脱氧血红蛋白浓度以及 细胞散射可以通过监测光的时空变化来成像 组织的吸收和散射特性，使近红外光谱的特殊能力， 测量血液动力学、代谢和神经元对大脑激活的反应。这些 NIRS的功能使其成为功能磁共振成像和EEG/MEG在正常人研究中的有用补充。 生理学和病理学，正如我们过去的出版物和传播所证明的 这个计划的周期。 我们开发了实时连续波（CW）成像仪器， 通过重叠提供的改进的空间分辨率来测量大脑激活 测量和信号处理，以减少系统干扰 生理波动此外，我们开发了一个原型时域（TD）成像 一种系统，提供比CW更好的深度灵敏度和量化基线的能力 大脑的生理特性。NIRS社区目前的需求包括：1） 工具，以促进解释大脑激活图像的背景下， 成人和婴儿的解剖学;以及2）获得便携式TD成像仪器， 能够以>2 Hz的图像采集速率进行多光谱测量（必要时 以克服生理干扰）。此外，NIRS的良好时间分辨率 使我们能够很好地理解和设计算法来过滤信号干扰， 由心率、呼吸和较慢的血压波动引起。这 干扰是常见的功能磁共振成像，因此，我们建议转让的技术诀窍，从我们的近红外光谱 功能磁共振成像的努力，以更好地过滤这种系统性的生理干扰，使探索 这些系统因素（包括大脑自动调节）和改善对比度- 脑激活的功能磁共振成像研究中的背景比。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Near Infrared Spectroscopy (NIRS) is a non-invasive, non-ionizing, and inexpensive monitoring and imaging technique that uses near-infrared light to probe tissue optical properties. Regional variations in oxy- and deoxy-hemoglobin concentration as well as cellular scattering can be imaged by monitoring spatial-temporal variations in the light absorption and scattering properties of tissue, giving NIRS the special ability to directly measure the hemodynamic, metabolic, and neuronal responses to brain activation. These capabilities make NIRS a useful complement to fMRI and EEG/MEG in studies of normal physiology and pathology, as evidenced by our publications and dissemination in the past grant cycles of this program. We have developed real-time continuous-wave (CW) imaging instrumentation for measuring brain activation with improved spatial resolution afforded by overlapping measurements and signal processing to reduce the interference from systemic physiological fluctuations. Further, we developed a prototype time-domain (TD) imaging system that affords better depth sensitivity than CW and the ability to quantify baseline physiological properties of the brain. Current needs of the NIRS community include: 1) tools to facilitate interpretation of the brain activation images in the context of brain anatomy in adults and infants; and 2) access to portable TD imaging instrumentation that enables multispectral measurements with an image acquisition rate of >2 Hz (necessary to overcome physiological interference). Further, the good temporal resolution of NIRS has enabled us to comprehend well and design algorithms to filter the signal interference that arises from heart rate, respiration, and slower blood pressure fluctuations. This interference is common to fMRI and thus we propose to transfer know-how from our NIRS effort to fMRI to better filter this systemic physiological interference, enabling exploration of these systemic factors (including cerebral autoregulation) and improving the contrast- to-background ratio in fMRI studies of brain activation.