Breaking new ground on ’untapped’, alternative brain imaging technique

Western's new Optical Neuroimaging Research Group (ONRG, pronounced ’
Western's new Optical Neuroimaging Research Group (ONRG, pronounced ’on-ergy’) is dedicated to unlocking functional near-infrared spectroscopy (fNIRS), an emerging technique also known as optical neuroimaging. (Western Institute of Neuroscience)
A new research group is paving Western’s way into a domain with potentially life-changing implications for our access to brain scanning technology.

In 2006, Western neuroscientist Adrian Owen found landmark evidence for the consciousness of a patient in a vegetative state when a functional magnetic resonance imaging (fMRI) scan revealed her brain activity after his team told her to imagine herself playing tennis.

This demonstrates the possibilities of brain scanning, but also reveals the limitations of fMRI as a neuroimaging technique. Namely, most of Owen’s patients couldn’t interrupt their life-sustaining care long enough to enter a multimillion dollar, 60-centimetre tube with 60,000 times the Earth’s magnetic field. This kept their true diagnoses and chances for recovery a mystery.

Examples such as this reveal the value of an alternative imaging technique that uses light rather than magnetic fields to image the human brain. Support from BrainsCAN coupled with the excitement over this portable, affordable, and patient-friendly technique led to the formation of the Optical Neuroimaging Research Group (ONRG, pronounced "on-ergy") at Western. 

Jody Culham, Canada Research Chair in Immersive Neuroscience

"We’re dedicated to unlocking the potential of functional near-infrared spectroscopy (fNIRS), an emerging technique also known as optical neuroimaging," said ONRG lead researcher Jody Culham, psychology professor and Canada Research Chair in Immersive Neuroscience. "We believe we’ve only just scratched the surface of fNIRS’ possible applications, and that Western is ideally positioned to push optical neuroimaging forward."

According to Keith St. Lawrence - a medical biophysics professor who’s developed devices for ONRG - fNIRS works by shining invisible light through a patient’s skull. Although much of this light is absorbed by the skin, hair, and skull, enough breaks through that it can bounce down into a patient’s brain and back out into the device’s detectors.

Since blood absorbs that light differently when its oxygenated, ONRG can garner similar blood oxygen data as an fMRI without needing the cumbersome, immovable device. Another system developed by St. Lawrence aims to determine the actual flow of blood in the brain, a crucial metric to monitor the signs of secondary brain injury in patients in intensive care units. 

Because fNIRS devices need only cover the head, wearers can move without corrupting the data, which opens new possibilities for research into helping stroke patients recover mobility. They’re portable enough for researchers like Owen to simply bring them to patients’ beds without risking their health. They’re also more cost-effective, allowing for expanded use in remote areas miles away from an fMRI scanner.

Post-doctoral associate Androu Abdalmalak and Farah Kamar removing NIRScout device from study participant Rasa Eskandar’s head (Mason Zimmer)

FNIRS can also be used to study diverse types of research participants. fNIRS works well with children and infants, especially because they have thinner skulls. Without the magnetic needs of fMRI, fNIRS is also safe for patients with prosthetic limbs, pacemakers, metal implants, and cochlear implants. fNIRS can even be used with multiple people simultaneously, enabling researchers to study social interactions such as those between a parent and child.

"There’s no more danger to this than going outside on a sunny day," said Culham.

Although fNIRS is limited in how precisely it can probe the brain, its untapped potential presents opportunities to mitigate that issue. That’s the goal of an experimental device called the Kernel Flow system and Western is one of just 23 global tests sites chosen by the manufacturer to assess its effectiveness.

Last month, ONRG hosted a conference called WestNIRS to bring the Western fNIRS community together with partners from industry and with other high-profile fNIRS researchers.

In Culham’s words, " What we’re really hoping to do with this is to build a name for Western in this domain."