Effect of Human Brain Edema on Light Propagation: A Monte Carlo Modeling Based on the Visible Chinese Human Dataset

Brain edema originates from the excessive accumulation of cerebrospinal fluid (CSF) in the brain attributing to brain trauma or nontrauma diseases such as cancer, ischemic stroke, meningitis, and encephalitis. The high intracranial pressure could extrude the vessels in brain and block the blood circulation, yielding the risk of intracranial hemorrhage (ICH). In this study, we investigated the feasibility of utilizing functional near infrared spectroscopy (fNIRS) for brain edema inspection through Monte Carlo simulations over the head model of the Visible Chinese Human dataset. The outstanding influence of the development (4 levels) of edema and the occurrence of ICH on the light migration were observed. With the increase of CSF volume, the results show a strong linear relationship between the volumes of CSF and the intensities of the detected signal and the deeper penetration of photons. An outstanding contrast was also observed before and after the occurrence of ICH. The study revealed that fNIRS holds promise to be an easy and reliable solution for inspecting edema aggression inside brain through the observation on the variation of optical signals, and is very suitable for continuous bedside inspection.