Developing Methods for Precision High-Density Diffuse Optical Tomography

COEX 

Neuroimaging research has traditionally approached data reliability through large-N consortium studies. However, in recent years, precision mapping studies, focusing on obtaining a high signal-to-noise ratio from a small group of individuals, have opened new avenues of exploring brain function [1]. Precision mapping takes a subject-specific approach to localize spatial and organizational variability in brain networks [2,3]. Although widely known in functional magnetic resonance imaging (fMRI) literature, this approach is yet to be established in optical imaging. In this study, we demonstrate the effectiveness of using High-Density Diffuse Optical Tomography (HD-DOT) to generate high-fidelity single-subject cortical maps [4]. HD-DOT is an optical imaging technique that uses dense, regularly spaced arrays of sources and detectors to obtain overlapping measurements of the underlying neuronal activity based on the absorption properties of hemoglobin in the blood [5-8]. We use an imaging system consisting of 128 sources and 125 detectors, with over 2500 measurements providing state-of-the-art HD-DOT image quality and extended cortical coverage (with a flatfield depth sensitivity >50% max, that extends to 20 mm beneath the scalp surface). Unlike fMRI, HD-DOT has a significant advantage of conducting scans while seated comfortably in a quiet and naturalistic environment.