Study of photon migration with various source-detector separations in near-infrared spectroscopic brain imaging based on three-dimensional Monte Carlo modeling

Abstract

We have simulated photon migration with various sourcedetector separations based on a three-dimensional Monte Carlo code. Whole brain MRI structure images are introduced in the simulation, and the brain model is more accurate than in previous studies. The brain model consists of the scalp, skull, CSF layer, gray matter, and white matter. We demonstrate dynamic propagating movies under different source-detector separations. The multiple backscattered intensity from every layer of the brain model is obtained by marking the deepest layer that every photon can reach. Also, the influences of an absorption target on the brain cortex are revealed.

Depth-compensated diffuse optical tomography enhanced by general linear model analysis and an anatomical atlas of human head

“…It is known that optical sensitivity in DOT has an approximately exponential decay with increased depth (Lee et al, 2005; Dehghani et al, 2009a), which makes DOT measurements hypersensitive to hemodynamic fluctuations in the scalp rather than to the more pertinent signals from the brain. The ill-posed sensitivity matrix causes positional errors in image reconstruction since the severe sensitivity decay biases the reconstructed brain activation towards the superficial layer.…”

Segmentation of scalp, skull, CSF, grey matter and white matter in MRI of mouse brain

“…The histogram of segmented skull is given by (1). S is according to the value in 08-0.85, the value of I is 65.…”

“…The most effective method to study the light intensity distribution inside the complex and turbid tissue is Monte Carlo [1,2,3,4,5].…”

Time-Domain Functional Diffuse Optical Tomography System Based on Fiber-Free Silicon Photomultipliers

“…When we simulated the inclusion at increasing depths, we retrieved the perturbation quite well localized both in x and y. Disregarding the superficial artifacts, the most relevant ∆µ a variations are localized correctly in z down to 10 mm, but reconstructed at a lower depth than desired for z = 15 mm. Nevertheless, this issue is quite common in tomographic reconstructions, since the sensitivity is lower at increasing depth [45,46]. Unfortunately, for z = 20 mm, the perturbation seems invisible to the system.…”

“…Instead, as long as it is placed outside this boundary (i.e., a few mm), it is not properly detected anymore, as visible in the y = 75 mm position. Nevertheless, this issue is quite common in tomographic reconstructions, since the sensitivity is lower at increasing depth [45,46]. Unfortunately, for z = 20 mm, the perturbation seems invisible to the system.…”