Juan Cebral's complex computer model does more than simply show blood
swirling in a brain aneurysm's labyrinthine pattern; it helps doctors determine whether the aneurysm is about to rupture and needs surgery.
Cebral, a professor at George Mason University's Center for Computational Fluid Dynamics, joined George Mason's Bioengineering Department in August 2014 where he studies fluids and how they move. He works with surgeons and other researchers to map out how blood flows in the brain, specifically in aneurysms. Brain aneurysms happen when blood bulges against a weak arterial wall and creates what resembles a balloon in the artery. Their cause is unknown.
Cebral is working with Inova Fairfax Hospital; the University of California, Los Angeles; the Mayo Clinic; the Buenos Aires, Argentina-based Clinical Institute ENERI; and Philips Healthcare in the Netherlands.
"I feel very excited that maybe my work will help doctors and patients," says Cebral. "If you look at the history of medical advances, doctors and scientists working together have made these advances. The doctors usually don't have the time to do research. The scientists need patients to do the research. It's difficult to get the right combination."
Technology is catching up with the complexity of the human brain, making it possible to study the interaction between blood flow and neurons. Past models were idealized, says Cebral, who earned his doctorate in computational fluid dynamics from Mason in 1996. "For instance, when you build a glass model of an aneurysm, it's just a straight glass tube with an aneurysm, and that never happens in the human body."
But now computerized models are a wonder of colors, and Cebral's models give surgeons a picture of the aneurysm that they wouldn't have had otherwise. He starts with the gray x-ray image of a
patient's aneurysm and transforms it into swirling colors to show the complex blood flow. Blue is normal blood flow, while red shows problematic blood flow. It can take a day or two to build a complex model and then another day to run the simulation.
"You can use the arterial geometry of specific patients and then you can simulate what that blood flow looks like," Cebral says. "You can study specific flow dynamics. We can provide some information that the doctors don't have today, which is the fluid dynamics of each individual patient."
About 5 to 8 percent of people have brain aneurysms, but less than 1 percent of aneurysms rupture every year, Cebral says. Intervention is risky, and it may not be worth taking that risk if the aneurysm isn't going to rupture.
"So the first question we need to ask is, which aneurysm is most likely to rupture?" Cebral says. His computer models work to answer that question by measuring the force of blood on the arterial wall and compiling statistics of the results.
"With that information we look at what happened with these aneurysms. Did they rupture? Did they not rupture? We look for the conditions in ruptured aneurysms and how they are different from the conditions in unruptured aneurysms. If we find that, for instance, an unruptured aneurysm has
A version of this story by Michele McDonald appeared in Bioengineering New (fall 2014)