
Robarts Research Institute trainees John Baxter, left, and Dante Capaldi turned morning coffee into an award-winning collaboration focused on developing a new image-processing technique to better detect lung function using magnetic resonance imaging. Capaldi is a Schulich School of Medicine & Dentistry PhD and MClSc candidate supervised by Medical Biophysics professor Grace Parraga. Baxter recently completed his doctorate at Schulich in Biomedical Engineering under Medical Biophysics professor Terry Peters.
At 10:30 a.m. on weekday mornings, Robarts Research Institute trainees come together for coffee and conversation. While it is an informal social opportunity, given the environment, science and collaboration often come up.
And it was such a chance encounter over coffee that brought John Baxter and Dante Capaldi together on an award-winning research project.
“We were chatting about hot yoga to start,” Capaldi said with a laugh, reflecting on the start of their research partnership. “The social aspect of being trainees in the same building helps build these type of connections.”
Capaldi is a Schulich School of Medicine & Dentistry PhD and MClSc candidate supervised by Medical Biophysics professor Grace Parraga. Baxter recently completed his doctorate at Schulich in Biomedical Engineering under Medical Biophysics professor Terry Peters.
Their collaborative research efforts are focused on developing a new image-processing technique to better detect lung function using magnetic resonance imaging (MRI), and the duo recently received a Trainee Research Prize from the Radiological Society of North America (RSNA).
The partnership unfolded in 2016 from improvements Capaldi was considering for the work he was completing.
“When you’re stuck on something, that’s the best time to collaborate,” Baxter said.
Capaldi’s work focuses on developing a non-contrast enhanced method to identify and measure lung function using MRI. “It’s difficult to image the lungs using MRI because you’re imaging a void,” he explained. “This is why we use contrast agents like hyperpolarized gases.”
But hyperpolarized gases are expensive, and availability can vary across research and clinical settings, prompting Capaldi to consider other ways to measure lung function.
Using MRI, he acquires images as the subject breathes normally. By aligning images at different phases of the breathing cycle, he then pulls out aggregate signals to detect changes in air volume within the lung during tidal breathing, which provides information about lung function.
However, the algorithm Capaldi was initially using to align and process image sequences was not optimized for high throughput patient data, making it difficult to translate this approach clinically.
This is where Baxter’s expertise in image processing came in – and their collaboration grew from there.
“The collaboration really took off, and we started looking at how we were creating the images in the first place,” Baxter said. “We collected data and refined and experimented with several techniques. It was a really interesting period.”
With a group of study volunteers – 23 asthmatics and seven healthy individuals – Baxter and Capaldi completed a final test of their imaging processing technique and compared it to the technique using contrast agents.
“We had the big advantage of being at Robarts, with access to ‘exotic’ contrast agents, enabling us to compare directly between an inhaled contrast agent and a free-breathing technique,” Capaldi said.
The results were submitted in a manuscript to the RSNA, leading to the international award. Capaldi will present the research findings at the RSNA’s conference Friday in Chicago.
“The clinical advantage of this work is people don’t have to hold their breath during imaging, they can naturally free breathe over the period of time,” Capaldi said. “Because we’re using techniques that already exist in most hospitals, our work can be easily translated from Robarts to anywhere with an MRI.”
Baxter continued, “When you consider our patient population has some form of lung dysfunction or disorder, such as asthma, it’s very difficult to hold your breath. Having a free-breathing, non-contrast enhanced approach is not only more accessible for settings that don’t have a hyperpolarizer readily available, but also allows us to process patients who wouldn’t otherwise be capable.”
The trainees credit the environment at Robarts for supporting a collaborative spirit and facilitating trainee research.
“At Robarts, we pride ourselves on creating novel imaging techniques, and collaboration is really key to moving imaging research forward,” Baxter said.