Postdoctoral scholar awarded fellowship for research transforming acute stroke triage
By Pamela Hyde
When a patient arrives at the hospital showing signs of a stroke, every minute counts. At the Foothills Medical Centre, the internationally acclaimed stroke team immediately begins assessing the patient when they arrive so that treatment can begin as soon as possible.
“Time is brain — you lose 2 million brain cells per minute during a stroke due to a blood clot in the brain,” says Christopher d’Esterre, postdoctoral scholar and recipient of the 2015 T. Chen Fong Fellowship in Medical Imaging Science. “You need to have information quickly, and it has to be accessible and it has to be right, or else things will go wrong in a flash.”
d’Esterre is researching computed tomography (commonly known as CT) perfusion scanning for quick assessment of acute stroke, and how it can inform treatment.
“With CT perfusion, you inject a small amount of an inert liquid into the blood and take a picture of the brain every few seconds as it travels to the affected area. This liquid gives the image contrast so that you can see blood vessels and blood velocity,” he explains. “Using a very fast computer and a little bit of complex math, we generate blood flow images of the brain. This tells us what tissue is dead, what tissue is critical, and what tissue is not affected. We can also get a sense of whether the patient is at risk of bleeding into the brain.”
The stroke team is also working on constructs that can tell them about the characteristics of the blood clot in the brain. According to d’Esterre, “the constructs tell us where the clot is is, how long it is, and whether it can be broken down using a clot-busting drug or whether it needs to be surgically removed. Surgical removal is more invasive but most effective, as shown in the recent ESCAPE trial.”
Improving process behind stroke treatment triage
The primary goal of d’Esterre’s research is to improve the decision-making process for stroke treatment triage at Foothills and around the world. “We’re trying to develop easy to interpret scoring methods based on imaging that can help clinicians make a decision quickly and correctly, and have it standardized everywhere,” he says.
“Chris d’Esterre is a bright young scientist in the early stages of his career, and is already part of team that is transforming health outcomes for all Canadians,” says Ed McCauley, vice-president (research). “He exemplifies the opportunities that exist for University of Calgary postdocs to contribute to world-changing research. We are thrilled that he has been awarded this fellowship.”
Using an example of a stroke patient in Lethbridge, d’Esterre explains the role of CT perfusion in the critical first moments of triage. In the scenario, the patient is over an hour away, so understanding how and when brain tissue will be affected is paramount.
“We have to decide whether we transport the patient to the Foothills hospital where we have the ability to remove the clot surgically, or if we want to keep the patient in Lethbridge. Surgical intervention isn’t currently possible in Lethbridge, but the clot-busting drug may have an equal probability of dissolving the blood clot as does surgical intervention – we need to determine this probability and act accordingly,” says d’Esterre. “Imaging is very important in making this decision as it will tell us the probability of both the drug dissolving the blood clot, and how much brain will be alive by the time the patient gets to Foothills hospital.”
According to Dr. Bijoy Menon, d’Esterre’s supervisor and member of the Hotchkiss Brain Institute, this research has already had a positive impact on the triage process.
“As stroke physicians, we rely heavily on imaging to make decisions, and Chris has used his skills and expertise with CT perfusion to tell us who are the right patients to have the mechanical clot-removal treatment,” he says.
Bridging communication gap between scientists and clinicians
When d’Esterre began his fellowship as part of the Calgary Stroke Program at the Foothills in 2013, he had his first hands-on clinical experience. “To see my basic science and physics background applied directly to stroke clinical care was the coolest aspect for me,” he says. “During my PhD training, I didn’t get to see the emergency stroke procedures in real time, and now I’m working directly with the neurologists who are making the acute treatment decisions.”
Menon credits d’Esterre’s fundamental science background with making him such an effective member of the stroke team.
“Chris has also been able to bridge what I call the communications gap between translational scientists and clinicians,” he says. “He brings expertise where he is able to talk to us and talk to the scientists through a common language, helping us build more collaboration.”
Learn more about advancements in acute stroke treatment at the University of Calgary.
The Dr. T. Chen Fong Postdoctoral Fellowship in Medical Imaging Science award honours the contributions made by Dr. Fong, and seeks to advance the field of medical imaging science. The fellowship is managed by the office of the vice-president (research).
Led by the Hotchkiss Brain Institute, Brain and Mental Health is one of six strategic research themes guiding the University of Calgary toward its ‘Eyes High’ goals.
This story originally appeared in the August 14th edition of UToday.