Re-imagining MRI: USask researchers develop technique for imaging knees in action

That’s the goal at the centre of University of Saskatchewan (USask) associate professor Dr. Emily McWalter’s (PhD) research project: developing a “functional” magnetic resonance imaging (MRI) technique that will give insights into knee joints while they are in use, leading to more accurate analysis and diagnoses of issues like early osteoarthritis.

“Mechanically, we want to see what’s going on inside the knee, what happens if we change the force on it,” said McWalter, an associate professor of mechanical engineering in the College of Engineering with a focus on biomedical engineering. “On the application side of things, how could this change diagnosis? Will we get better, more sensitive measures of tissue function if we measure when forces are applied?”  

An MRI is used to examine soft tissues and organs in ways that X-rays cannot. But traditional MRIs are conducted while the patient is lying down. For some key parts of your body — such as load-bearing joints like knees — an MRI while lying down might not provide the whole picture.

One of the main challenges of a functional MRI of the knee is that too much motion will disrupt the results. By testing using donated human knee tissue and a custom designed plastic force application device – as metal will also disrupt an MRI – McWalter and her team devised an MRI technique that will allow knees to be scanned while in use.  

Because of the size and complexity of an MRI machine, completely redesigning one for this kind of task isn’t an option. Instead, McWalter’s team aims to establish new scanning protocols and sequences — or different methods of capturing a variety of images to provide an accurate representation of the structure and function of the tissues being scanned.  

McWalter’s newly devised force application device and MRI scanning sequence has the potential to give researchers and doctors a more accurate-than-ever look at the inside of a knee while it is in use.  

Individuals who have had knee surgeries such as ACL repairs are more likely to acquire conditions like early-onset osteoarthritis and McWalter said developing all the tools and techniques for a functional MRI could help diagnose those concerns much earlier.

“We developed a new MRI sequence that gives us bright contrast from tissues that would normally be black on a regular MRI,” she said. “We want that signal so we can get better measures of tissue structure, which also tells us about tissue health. Using this new MRI sequence when forces are applied to the knee means that all the tissues important for proper function can be evaluated.”

The project received funding from the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant program, which supports creative and innovative research projects with long-term goals.  

McWalter said one of the biggest boons of the NSERC grant was the dedicated support to training students – the next generation of engineers and biomedical experts exploring MRI technology at USask.  

She said the grant would help her support a team of students to investigate this area of functional MRI scans.

“I’m excited about this scientific work, but I’m also really excited that I get to bring in more young people,” McWalter said. “I’m fortunate to have worked with some really exceptional trainees along the way.”

For more information, please contact:
Ashley Trask
USask Media Relations
ashley.trask@usask.ca
306-966-4522