Graphic of brain aneurysm

A better understanding of blood flow and brain aneurysms

A weak blood vessel in the brain is a dangerous thing. Six million Americans have one that bulges out like a bubble and fills with blood, creating a brain aneurysm. If it ruptures – as it does in about 30,000 people annually – it can result in a coma, permanent brain damage, paralysis or death.

To better diagnose and treat brain aneurysms, Roshan D’Souza, a UWM associate professor of mechanical engineering, is developing new methods of analysis for a special kind of magnetic resonance imaging technology: 4D Flow MRI.

Roshan D’Souza

Unlike traditional organ scans, 4D Flow MRI provides spatial 3D measurements of blood flow velocity and tracks its variation over time – the fourth dimension. D’Souza wants to use the shear stress that the flowing blood imposes upon a vessel’s wall as a biomarker for the potential growth of an aneurysm. This would indicate if and when treatment is needed to prevent rupture.

Because the resolution and raw data from the MRI scans aren’t of a high enough quality to be clinically useful, D’Souza is developing a new approach that merges two pieces of complementary information: flow physics simulations and actual data from the scan.

“It’s similar to how meteorologists produce storm warnings,” D’Souza says. “A high-resolution storm simulation based on a physics model receives updates from sensors that track an ongoing storm to generate improved predictions.” In this case, the MRI data update the parameters of the physics model to generate a higher-resolution image.

D’Souza and his collaborators at the Medical College of Wisconsin hope to eventually design clinical trials to quantify the new method’s benefits. And the brain is only the beginning.

“We can expand our research to 4D Flow MRI studies of the liver, heart and kidneys,” D’Souza says. “I think this method has the potential to make a real difference for many patients.”


(UWM Photo/Troye Fox)