Reconstruction algorithms for time-domain diffuse optical tomography imaging of small animals

该提案是关于开发有效的计算机程序（所谓的算法），以获得用于生物医学研究的小型实验室动物（小鼠）内部的3D图像。这里考虑的用于获得这些图像的技术是漫射光学断层扫描（DOT），这是一种非侵入性医学成像模式，其中来自激光的非电离光用于在动物皮肤上的几个点处照射动物。在其传播通过其身体之后离开动物的光再次在其皮肤上的几个位置处被测量（检测）。算法的任务是从这些表面测量数据中获得动物内部的3D图像。对于DOT来说，这是一个很难的数学问题，在获得图像之前，在现代台式计算机上可能需要几个小时才能解决这个问题。此外，我们的工作的一个特殊性是，我们诉诸于检测技术，所谓的时域光学测量，提供信息更丰富的数据。这具有提高所获得的图像的空间分辨率并使其更加定量的潜力，但是由于这种测量必须处理更多的数据，因此计算时间进一步增加。利用这些数据提示有效的数值技术，以减少我们的算法所需的计算能力。这项建议是关于发展这种技术，应导致减少计算时间的估计系数为10至100。这项研究很重要，因为小动物的3D临床前成像是生物医学研究的关键工具，可以研究疾病发展（癌症）和治疗（药物设计，治疗评估）的基本过程。这最终会影响可以向患病患者提供的治疗质量，从而改善他们的生活质量和预后。这里提出的研究计划将为DOT的最终用户提供更快的协议反馈，这在他们的日常工作中非常重要。值得注意的是，这里开发的光学成像允许研究无法用其他医学成像模式可视化的过程，从而补充这些其他模式。该方案将允许培养4名博士学位研究生，沿着启动5名学士学位研究生。

This proposal is about the development of efficient computer programs (so-called algorithms) to obtain images in 3D of the interior of small laboratory animals (mice) used in biomedical research. The technique considered here for obtaining these images is diffuse optical tomography (DOT), a non-invasive medical imaging modality whereby non-ionizing light from a laser is used to illuminate an animal at several points on its skin. The light exiting the animal after its propagation through its body is measured (detected) at several positions again on its skin. The task of algorithms is to obtain from such surface measurements data a 3D image of the interior of the animal. For DOT, this is a difficult mathematical problem whose solution may take up to several hours on modern desktop computers before an image is obtained. Furthermore, a particularity of our work is that we resort to a detection technique, so-called time-domain optical measurements, that provides for information richer data. This has the potential of improving the spatial resolution of the images obtained and making them more quantitative, but since more data must be handled with such measurements, the computing time is further increased. Exploiting such data prompts for efficient numerical techniques to reduce the computational power needed by our algorithms. This proposal is about the development of such techniques that should lead to a decrease in computing times by an estimated factor of 10 to 100. This research is important because 3D pre-clinical imaging of small animals is a key tool in biomedical research that allows studying fundamental processes involved in disease development (cancer) and treatment (drug design, therapy assessment). This ultimately has impacts on the quality of treatments that can be offered to diseased patients, thus improving their quality of life and prognostics. The research program proposed here will provide end-users of DOT with faster feedback on their protocols which is important in their daily duties. Notably, optical imaging as developed here, allows studying processes that cannot be visualized with other medical imaging modalities, thus complementing these other modalities. The proposal will allow training 4 doctoral degree students along with initiating 5 bachelor’s degree students to research.