Researchers Developing New Way to Predict Stroke Risk
Each year in the United States, as many as 100,000 people are at risk of debilitating or lethal strokes or mini-strokes caused by narrowing or blockage of their carotid arteries. Currently, there’s no reliable, noninvasive way to determine whether a patient with one of these conditions is likely to have a stroke.
“The best technology in use today is carotid duplex ultrasound, which reveals the degree of blood vessel narrowing and the size and location of plaque causing a blockage – both key causes of stroke,” says Geoffrey Vince, PhD, Chairman of Biomedical Engineering in Cleveland Clinic’s Lerner Research Institute. “But it cannot help predict a patient’s risk of stroke, making treatment challenging.”
Dr. Vince and his colleagues are working to change all that — by “seeing” strokes before they happen.
Two Types of Plaque
“We believe that the composition of plaque – whether of a fibrous material or cholesterol based – indicates the risk of stroke,” says Dr. Vince, who holds the Virginia Lois Kennedy Chair in Biomedical Engineering and Applied Therapeutics.
To determine the nature of the plaque, Dr. Vince says, his lab is using external ultrasound, the least invasive means.
“Our hypothesis is that cholesterol blockages are more dangerous than fibrous ones because they can burst,” he says. “It’s also important to know the plaque’s composition because surgery to remove a blockage has risks, including stroke –the very problem we are trying to prevent. If external ultrasound could determine the type of blockage, then the surgeon could decide whether an operation is necessary.”
New Technology Uses Color
The lab is developing external ultrasound imaging that can detect certain frequencies arising from blockages and transmit them to a computer. Current technology produces only grayscale images, which are less reliable for predicting stroke than color images would be. To understand the difference, compare a black-and-white printout with a high-resolution color photo, Dr. Vince says.
“Our device, the size of a cellphone, scans the artery from outside the patient’s body. It sends images that the computer uses to produce a kind of map with colors indicating whether the plaque is OK (fibrous) or dangerous (cholesterol),” he says.
Dr. Vince and his team are exploring the possibility of creating a database that will teach a computer to recognize plaque composition. The technology has potential as a diagnostic tool to guide therapy and eventually could become part of a patient’s annual checkup. If cholesterol buildup in the arteries is detected, the patient would be closely monitored and receive specifically tailored therapy.
“Philanthropic funding can help further our development of this technology, which could help avert strokes caused by unnecessary treatment and those arising from treatable blockages,” Dr. Vince says. “Although the technology may be complex, the idea is simple: The more we know, the more lives we can save.”