Fathi Faraneh, Mazdeyasna Siavash, Singh Dara, Huang Chong, Mohtasebi Mehrana, Liu Xuhui, Rabienia Haratbar Samaneh, Zhao Mingjun, Chen Li, Can Ulku Arin, Mos Paul, Bruschini Claudio, Charbon Edoardo, Chen Lei, Yu Guoqiang
IEEE Trans Med Imaging. 2025 Mar;44(3):1206-1217. doi: 10.1109/TMI.2024.3486084. Epub 2025 Mar 17.
To address many of the deficiencies in optical neuroimaging technologies, such as poor tempo-spatial resolution, low penetration depth, contact-based measurement, and time-consuming image reconstruction, a novel, noncontact, portable, time-resolved laser speckle contrast imaging (TR-LSCI) technique has been developed for continuous, fast, and high-resolution 2D mapping of cerebral blood flow (CBF) at different depths of the head. TR-LSCI illuminates the head with picosecond-pulsed, coherent, widefield near-infrared light and synchronizes a fast, high-resolution, gated single-photon avalanche diode camera to selectively collect diffuse photons with longer pathlengths through the head, thus improving the accuracy of CBF measurement in the deep brain. The reconstruction of a CBF map was dramatically expedited by incorporating convolution functions with parallel computations. The performance of TR-LSCI was evaluated using head-simulating phantoms with known properties and in-vivo rodents with varied hemodynamic challenges to the brain. TR-LSCI enabled mapping CBF variations at different depths with a sampling rate of up to 1 Hz and spatial resolutions ranging from tens/hundreds of micrometers on rodent head surfaces to 1-2 millimeters in deep brains. With additional improvements and validation in larger populations against established methods, we anticipate offering a noncontact, fast, high-resolution, portable, and affordable brain imager for fundamental neuroscience research in animals and for translational studies in humans.
为解决光学神经成像技术中的诸多不足，如时空分辨率差、穿透深度低、基于接触的测量方式以及耗时的图像重建等问题，已开发出一种新型的、非接触式、便携式、时间分辨激光散斑对比成像（TR-LSCI）技术，用于在头部不同深度对脑血流量（CBF）进行连续、快速且高分辨率的二维映射。TR-LSCI用皮秒脉冲、相干、宽场近红外光照射头部，并同步一个快速、高分辨率、门控单光子雪崩二极管相机，以选择性地收集通过头部具有更长光程的漫射光子，从而提高深部脑区CBF测量的准确性。通过将卷积函数与并行计算相结合，显著加快了CBF图的重建速度。使用具有已知特性的头部模拟体模以及对脑部有不同血流动力学挑战的活体啮齿动物对TR-LSCI的性能进行了评估。TR-LSCI能够以高达1赫兹的采样率以及从啮齿动物头部表面的数十/数百微米到深部脑区的1 - 2毫米的空间分辨率映射不同深度的CBF变化。随着在更大群体中针对既定方法进行进一步改进和验证，我们预计将提供一种非接触、快速、高分辨率、便携式且经济实惠的脑成像仪，用于动物基础神经科学研究以及人类转化研究。
