Noninvasive optical estimation of CSF thickness for brain-atrophy monitoring

TL;DR

This paper introduces a non-invasive optical method using time-resolved Near Infra-Red measurements to estimate CSF thickness, aiding in monitoring brain atrophy progression in dementia patients, offering a safer alternative to MRI or XCT.

Contribution

It presents a novel non-invasive approach based on tr-NIR measurements and realistic head models to estimate CSF thickness related to brain atrophy.

Findings

Time-resolved reflectance curves show slope changes with CSF increase.

Method demonstrates good sensitivity to CSF variation.

Potential for fast, non-invasive dementia progression monitoring.

Abstract

Dementia disorders are increasingly becoming sources of a broad range of problems, strongly interfering with normal daily tasks of a growing number of individuals. Such neurodegenerative diseases are often accompanied with progressive brain atrophy that, at late stages, leads to drastically reduced brain dimensions. At the moment, this structural involution can be followed with XCT or MRI measurements that share numerous disadvantages in terms of usability, invasiveness and costs. In this work, we aim to retrieve information concerning the brain atrophy stage and its evolution, proposing a novel approach based on non-invasive time-resolved Near Infra-Red (tr-NIR) measurements. For this purpose, we created a set of human-head atlases, in which we eroded the brain as it would happen in a clinical brain-atrophy progression. With these realistic meshes, we reproduced a longitudinal tr-NIR study exploiting a Monte-Carlo photon propagation algorithm to model the varying cerebral spinal fluid (CSF). The study of the time-resolved reflectance curve at late photon arrival times exhibited peculiar slope-changes upon CSF layer increase that were confirmed under several measurement conditions. The performance of the technique suggests good sensitivity to CSF variation, useful for a fast and non-invasive observation of the dementia progression.