Review of measurements and imaging of cytochrome-c-oxidase in humans using near-infrared spectroscopy: an update

Abstract

This review examines advancements in the measurement and imaging of oxidized cytochrome-c-oxidase (oxCCO) using near-infrared spectroscopy (NIRS) in humans since 2016. A total of 34 published papers were identified, with a focus on both adult and neonate populations. The NIRS-derived oxCCO signal has been demonstrated to correlate with physiological parameters and hemodynamics. New instrumentation, such as systems that allow the imaging of changes of oxCCO with diffuse optical tomography or combine the oxCCO measurement with diffuse correlation spectroscopy measures of blood flow, have advanced the field in the past decade. However, variability in its response across different populations and paradigms and lack of standardization limit its potential as a reliable and valuable indicator of brain health. Future studies should address these issues to fulfill the vision of oxCCO as a clinical biomarker.

Introduction to the Optics and the Brain 2023 feature issue

“…Diffuse optics can probe centimeters deep in human tissue with near-infrared light, to reach the living brain non-invasively. A review article [ 1 ] highlights the measurement of oxidized cytochrome-c-oxidase using a non-invasive optical imaging method of near-infrared spectroscopy (NIRS) in adults and neonates. Another study [ 2 ] using conventional hemoglobin NIRS shows that a virtual reality game task can modulate brain functional networks better than simple grasping movements.…”

“…Overall this special issue highlights the breadth of technologies and applications represented by the Optics and the Brain community, and the wide range of spatial scales and brain observables that can be measured or modulated by optical methods. The articles in this special issue represent a just small sample of the high-quality brain-related research published in Biomedical Optics Express recently [ 1 – 46 ]. We thank the Optica editorial board and staff for supporting this effort, and we express gratitude to the community at large for providing high quality submissions and reviews for this special issue.…”