By Adam Eggebrecht
A Brain Initiative workshop on the dissemination of non-invasive imaging technologies was held as a virtual meeting on February 18-19, 2021. The talks are currently available for streaming on YouTube at https://www.youtube.com/c/BRAINInitiative/featured.
Of particular note is a presentation by Dr. Shumin Wang, a Program Director for the Brain Initiative, who provided an overview of the funded projects on hemodynamic imaging. Highlighted projects include five magnetic resonance imaging projects, a magnetic particle imaging project, and three functional optical imaging projects. The optical projects are headed by Dr. David Boas, Dr. Maria Angela Franceschini, and Dr. Joe Culver.
Additionally, Dr. Lihong Wang has a project entitled, ‘Massively parallel high-speed 3D functional photoacoustic computed tomography of the adult human brain.’ A day’s worth of binge-watching fascinating talks are available at the link above. Here, we will briefly highlight the three optical projects.
David Boas of Boston University presented on his project, ‘The neuroscience of everyday world – A novel wearable system for continuous measurement of brain function.’ This work involves developing wearable multi-modal systems including the integration of eye tracking and EEG with fNIRS. Dr. Boas explains how these systems will be used for studies on walking, perceiving, and interacting not only in the lab but also out in the wild. Additionally, he discusses advancements in wearable high density caps including the NIRx Sport and ninjaNIRS, and exciting new developments with time domain fNIRS through the company Kernel. Maria Angela Franceschini of MGH at Harved presented on her project, ‘Time-gated diffuse correlation spectroscopy (DCS) for functional imaging of the human brain.’
Dr. Franceschini discusses the large team assembled to overcome the significant challenges involved in advancing time-resolved DCS to obtain improved signal to noise. Additionally, she discusses opportunities provided by using 1,064 nm photons to increase brain sensitivity. Very cool preliminary data on superficial hemodynamics as well as brain activity recorded at 10 Hz is presented. She then discusses some cool details on her team’s progress developing new detectors optimized for time resolved-DCS.
Joe Culver of Washington University in St. Louis presented on his project, ‘High-density diffuse optical tomography (HD-DOT) for decoding brain activity.’ Dr. Culver discusses challenges in moving from fiber-based HD-DOT systems to a wearable on-head design using smart optodes containing both LED sources and photodiode detectors. These smart optodes must match opto-electronic specifications for a low noise floor, wide dynamic range, and low cross talk throughout the system. Additionally, challenges in anatomy-data registration are discussed. Dr. Culver then walks through some studies on decoding brain activity recorded with HD-DOT in visual cortex using retinotopy and even throughout the brain using movie-driven audio-visual stimuli. All these presentations highlight the tremendous potential for next generation optical technology to advance fundamental neuroscience and clinical care throughout the lifespan.