MRI-Compatible Diffuse Optical Tomography System

兼容 MRI 的漫射光学断层扫描系统

• 批准号: 6801990
• 负责人: ANDREAS H HIELSCHER
• 金额: $ 47.79万
• 依托单位: COLUMBIA UNIV NEW YORK MORNINGSIDE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-15 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6801990
• 关键词: bioimaging /biomedical imaging; biomedical equipment development; image processing; laboratory rat; magnetic resonance imaging; optics; oximetry; three dimensional imaging /topography; tomography

DESCRIPTION (provided by applicant): The overall goal of this proposal is the development of a three-dimensional optical tomographic (OT) near-infrared imaging system for oximetry in small animals. The system will be designed to allow for co-registration of OT data and magnetic resonance (MR) imaging data, but may also be used as a stand-alone optical imaging unit. While commercial systems that perform optical blood-oxygenation monitoring exist, these instruments have not been optimized for small animal studies and have not been combined with MR imaging systems. Furthermore, the available devices often operate with a limited number of sources and detectors, do not generate three-dimensional volumetric images, and the image reconstruction is performed with diffusion-theory-based algorithms. It is well known, however, that diffusion theory does not fully account for the effects of light propagation in small biological media (diameter 1-2 cm), because at these dimensions the diffusion approximation to the more generally applicable theory of radiative transfer is not sufficiently accurate. The proposed work attempts to overcome the current shortfalls and develop a near-infrared optical imaging system that can be used in combination with standard small animal MR scanners. The main hypothesis of this project is that current limitations of optical tomographic imaging can be addressed by implementing a three-dimensional frequency-domain reconstruction scheme that is based on the equation of radiative transfer (ERT). This algorithm will be implemented and used in conjunction with a commercially available frequency-domain measurement system (IAMGENT from ISS, Urban-Champaign, IL), which will be adapted to collect data inside an MR small animal imager. By co-registering optical and MR data one can combine the benefits of MR's high-spatial-resolution, with OT's high temporal resolution and its capability of separating oxyhemoglobin, deoxyhemoglobin, and blood volume effects. For this project we will pursue the following three specific aims: (1) Develop and numerically validate of a three-dimensional, transport-theory-based, frequency-domain image reconstruction code for diffuse optical tomography; (2) Validate and evaluate the optical tomographic imaging system (code and instrument) in a small animal magnetic resonance imager; and (3) Compare frequency-domain and steady-state, transport-theory based optical tomography with diffusion-theory-based optical tomography. This comparison will quantify the advantages and disadvantages of these different optical imaging modalities.

描述（由申请人提供）：该提案的总体目标是开发用于小动物血氧测定的三维光学断层（OT）近红外成像系统。该系统的设计允许同时配准 OT 数据和磁共振 (MR) 成像数据，但也可以用作独立的光学成像单元。虽然存在进行光学血氧监测的商业系统，但这些仪器尚未针对小动物研究进行优化，也未与 MR 成像系统相结合。此外，可用的设备通常使用有限数量的源和探测器进行操作，不生成三维体积图像，并且图像重建是使用基于扩散理论的算法执行的。然而，众所周知，扩散理论并没有完全解释光在小型生物介质（直径 1-2 厘米）中传播的影响，因为在这些尺寸下，更普遍适用的辐射传输理论的扩散近似并不适用。足够准确。 拟议的工作试图克服当前的不足，开发一种可与标准小动物磁共振扫描仪结合使用的近红外光学成像系统。该项目的主要假设是，当前光学断层成像的局限性可以通过实施基于辐射传输方程（ERT）的三维频域重建方案来解决。该算法将与商用频域测量系统（伊利诺伊州香槟市国际空间站的 IAMGENT）结合使用和实施，该系统将适用于收集 MR 小动物成像仪内的数据。通过共同配准光学和 MR 数据，人们可以将 MR 的高空间分辨率的优点与 OT 的高时间分辨率及其分离氧合血红蛋白、脱氧血红蛋白和血容量效应的能力结合起来。对于这个项目，我们将追求以下三个具体目标：（1）开发并数值验证用于漫射光学断层扫描的三维、基于传输理论的频域图像重建代码； （2）验证和评估小动物磁共振成像仪中的光学断层成像系统（代码和仪器）； (3) 比较频域和稳态、基于传输理论的光学层析成像与基于扩散理论的光学层析成像。这种比较将量化优点和缺点 这些不同的光学成像方式。