Real-time tracking of brain oxygen gradients and blood flow during functional activation

Sang Hoon Chong; Yihong Ong; Mirna El Khatib; Srinivasa Rao Allu; Ashwin B. Parthasarathy; Joel H. Greenberg; Arjun G. Yodh; Sergei A. Vinogradov

doi:10.1117/1.NPh.9.4.045006

28 November 2022 Real-time tracking of brain oxygen gradients and blood flow during functional activation

Sang Hoon Chong, Yihong Ong, Mirna El Khatib, Srinivasa Rao Allu, Ashwin B. Parthasarathy, Joel H. Greenberg, Arjun G. Yodh, Sergei A. Vinogradov

Author Affiliations +

Neurophotonics, Vol. 9, Issue 4, 045006 (November 2022). https://doi.org/10.1117/1.NPh.9.4.045006

Abstract

Significance

Cerebral metabolic rate of oxygen (CMRO₂) consumption is a key physiological variable that characterizes brain metabolism in a steady state and during functional activation.

Aim

We aim to develop a minimally invasive optical technique for real-time measurement of CMRO₂ concurrently with cerebral blood flow (CBF).

Approach

We used a pair of macromolecular phosphorescent probes with nonoverlapping optical spectra, which were localized in the intra- and extravascular compartments of the brain tissue, thus providing a readout of oxygen gradients between these two compartments. In parallel, we measured CBF using laser speckle contrast imaging.

Results

The method enables computation and tracking of CMRO₂ during functional activation with high temporal resolution (∼7 Hz). In contrast to other approaches, our assessment of CMRO₂ does not require measurements of CBF or hemoglobin oxygen saturation.

Conclusions

The independent records of intravascular and extravascular partial pressures of oxygen, CBF, and CMRO₂ provide information about the physiological events that accompany neuronal activation, creating opportunities for dynamic quantification of brain metabolism.

CC BY: © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 International License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Citation Download Citation

Sang Hoon Chong, Yihong Ong, Mirna El Khatib, Srinivasa Rao Allu, Ashwin B. Parthasarathy, Joel H. Greenberg, Arjun G. Yodh, and Sergei A. Vinogradov "Real-time tracking of brain oxygen gradients and blood flow during functional activation," Neurophotonics 9(4), 045006 (28 November 2022). https://doi.org/10.1117/1.NPh.9.4.045006

Received: 6 August 2022; Accepted: 1 November 2022; Published: 28 November 2022

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