Engineering and the Brain
Engineering and the brain may seem poles apart, but some of the most advanced technologies revealing the workings and structure of the human brain are being developed by engineers.
McMaster’s Mike Noseworthy is one of those redefining how we see the brain, literally. An MRI physicist turned biomedical engineer, Mike heads the Imaging Research Centre at McMaster’s Brain-Body Institute, where researchers are working to advance our understanding of how the mind, brain and body work together to influence health and disease.
Armed with one of the most sophisticated MRI scanners available, Noseworthy and his nine PhD students are pushing the limits of brain imaging in ways we’ve never seen before. They’re writing new software and building hardware, mapping out new algorithms, and building prototypes for everything from ergometric bikes that monitor how exercise affects the brain to sensor-equipped helmets that will alert hockey players to traumatic brain injury (TBI) at its earliest stages.
“We build stuff,” says the associate professor, electrical and computer engineering. “Our students are trained not only in biomedical engineering, but also in anatomy, physiology and electrical and computer engineering. That’s what makes the McMaster biomedical engineering program so fantastic.”
Noseworthy’s own CV reveals a storied past. He got into imaging as a graduate student in the mid-1980s, when MRIs were still in their infancy. Jobs were scarce then, and he ended up working as a pig farmer before landing a position imaging animals for the Ontario Veterinary College at the University of Guelph.
“You had to be a physicist to run the equipment back then. I did everything. I was building stuff, fixing stuff, doing research imaging on lab animals and clinical imaging of people’s pets. Every day was a new challenge, and there was no one you could call for advice – I think there were only three human MRI scanners in Canada at the time.”
He did his post-doctoral fellowship in imaging physics at the University of Toronto, then spent three years as a medical physicist at the Hospital for Sick Children, where he cut his clinical teeth and built his skills in neurosurgical planning. “My job was to map out key areas of the brain so neurosurgeons could choose the best surgical approaches.”
When the offer came to head up McMaster’s new Imaging Research Centre, Noseworthy jumped at the chance. “How could I refuse an opportunity to run my own imaging lab with an MRI dedicated 24/7 to research? I was used to doing my research at midnight on clinical scanners that were unavailable during the day, so this was heaven.”
He arrived with his graduate and post-doctoral students in tow to a setup that was less than ideal. “It was just a big open area with a magnet in it. I sat in a carrel like a student, with piles of computers and books all around, running different software programs. We had 18 or 19 computers and it would get so hot in there that the students would strip down to their undies,” he laughs, quickly adding that back then it was an all-male group.
“I remember thinking how do we grow this. I knew that non-invasive imaging technology was the way to go. I knew we had to build that.”
And build it he did, with funding from the Natural Sciences and Engineering Research Council (NSERC), the Canada Foundation for Innovation (CFI) and the Canadian Institutes of Health Research (CIHR), plus a $2.5 million lab upgrade from St. Joseph’s Healthcare Hamilton where the lab is located.
The lab’s original MRI scanner has since been upgraded to a high-powered model that is twice the strength of a clinical model. It’s one of only a handful in the country earmarked solely for research, and the only one equipped with both broadband radio frequency and a proton decoupler.
The MRI scanner shares space with the region’s only PET/CT (positron emission tomography/computed tomography) scanner, an electroencephalography (EEG) system that can operate simultaneously with MRI, plus ultrasound and real-time optical imaging. There are also labs for building, testing and repairing custom magnetic resonance (MR) imaging coils and developing customized imaging phantoms that allow for fine-tuning various imaging devices.
But the equipment, while instrumental, is merely an agent for what Noseworthy and his research team do best – refine and combine the latest neuroimaging techniques to produce high-resolution brain maps and images showing structural, functional and metabolic abnormalities at their earliest stage.
Using a variety of advanced imaging methodologies – susceptibility-weighted imaging (SWI), diffusion tensor imaging (DTI), blood-oxygen-level dependent (BOLD) fractal dimension mapping – Noseworthy and his students are able to highlight specific areas of the brain that are improperly functioning or damaged, visualizations that would not be picked up by a conventional MRI scan.
SWI, for instance, produces high-resolution images sensitive to blood and iron, so micro-hemorrhages common to mild traumatic brain injury (mTBI) are easier to detect. Concussions and other forms of (mTBI) account for about 75% of TBIs, and can cause severe and longlasting effects. Yet fewer than one per cent of these injuries show up on routine MRI and CT scans.
“I saw a teenager who suffered a head injury, and a year and a half later he was still not right,” says Noseworthy. “He had gone from being an A student to a D student, but his MRI scans were normal. Only when we used SWI were we able to detect the tiny previous hemorrhage spots.”
SWI is also being used to detect microbleeds linked to acute stroke and dementia, and is proving useful in quantifying iron content for multiple sclerosis (MS) and Parkinson’s disease. In a similar fashion, BOLD fractal dimension mapping helps to zero in on Alzheimer’s disease, which is linked to a reduction in (healthy) chaotic brain activity, while DTI captures subtle white matter abnormalities seen in mTBI and a host of other neurodegenerative diseases, including epilepsy and schizophrenia.
“Being able to find abnormalities in a person’s brain when routine clinical scans show the brain as normal really hits home with people who have had a brain injury,” says Noseworthy. “They know there’s something wrong, but the doctors say there isn’t.”
The Centre is also the only Canadian imaging research lab equipped with MRI-compatible exercise bikes for the study of both adults and children. Unlike routine MRI scans where subjects are told to keep still, patients are asked to put pedal to the metal to show good solid movement.
“It is well known that patients recovering from TBI often experience a recurrence of TBI symptoms with the onset of exercise,” says Noseworthy. “By measuring what is happening in the brain before, during and after exercise, we can more carefully monitor a patient’s recovery.”
He believes the potential to improve diagnosis, management and surgical precision is limitless. “Non-invasive neuroimaging is moving ahead by leaps and bounds. And because it’s only magnets and radiowaves, it can be used over and over again with no risk to the patient.
“The future will bring even better approaches with higher sensitivity that will improve our ability to diagnose and manage a whole range of diseases that we still don’t have an answer for.”