Department of Biomedical Engineering
Each year about 800,000 Americans experience a new or recurrent stroke, or “brain attack.” Many strokes are caused by a blockage in the arteries carrying blood to the brain; if oxygen carried by blood cannot get to the brain, the result is brain damage and often other physical harm. Carotid stenosis – a blockage caused by plaque build-up in the carotid arteries on either side of the neck – is a significant but treatable risk factor for stroke. In the US, physicians perform more than 100,000 active procedures each year to clear such blockages. However, it is estimated that another 2%-8% of the US population have some carotid stenosis, but do not show the usual symptoms (including high blood pressure, lightheadedness, etc.), making it unclear whether to treat them urgently or not.
Such stenosis can often be detected, without surgery (noninvasively), by devices outside the body that focus ultrasound waves onto targeted arteries. The most often used technique, carotid duplex ultrasound, can visualize the location and extent of plaque and detect changes in blood flow, allowing the doctor to determine how much plaque build-up is already in the arteries. This technique, although valuable, cannot give the doctor enough information to say what kind of plaque is in there. Unstable plaques, from which pieces may break off to block the entire blood flow within an artery, are more dangerous: these must be treated immediately to prevent a stroke. If a plaque is stable, it presents less risk. So it is essential that medical personnel find out quickly and reliably which type is threatening the patient.
Dr. Vince’s team is developing computer software that can do more to analyze ultrasound images of carotid arteries. The new system creates a spectrum where different colors indicate how, where, and how bad the plaque build-up is by using information from scattered ultrasound points that is obtained but not considered during the creation of standard ultrasound images. The team’s goal is to provide a tool that will predict which patients are at increased risk of having a stroke and will aid the physician in determining the best treatment approach.
Summary: Dr. Vince and his team are developing a noninvasive approach to determine quickly an individual patient’s risk of having a stroke and allow the physician to deliver the most effective therapy.
See also: Vince Lab