Ultrasound device to identify 'vulnerable' plaque

Imagine an ultrasound device that could help identify unsafe arterial plaque that is at high risk of breaking off and causing heart attack or stroke.

Researchers from North Carolina (NC) State University and University of North Carolina at Chapel Hill have developed an ultrasound device that will help identify "vulnerable" plaque that increases risk of heart attack or stroke.

Plaque builds up in arteries as we age.

Some types of plaque are deemed "vulnerable", meaning that they are more likely to detach from the artery wall and cause heart attack or stroke.

"Existing technologies are capable of determining if plaque is present in the arteries, but can not tell whether it is vulnerable. And that makes it difficult to assess a patient's risk," explained Paul Dayton, a professor in the joint biomedical engineering department at NC State and Chapel Hill.

The goal was to develop something that could effectively identify which plaques are vulnerable.

There are already two ultrasound techniques that can help identify vulnerable plaques but both depend on the use of contrast agents called "microbubbles".

"The problem is that existing intravascular ultrasound technology does not do a very good job in detecting contrast agents," added Xiaoning Jiang, an associate professor at NC State.

The researchers have now developed a new prototype of dual-frequency intravascular ultrasound transducer which transmits and receives acoustic signals.

"Operating on two frequencies allows us to do everything the existing intravascular ultrasound devices can do, but also makes it much easier for us to detect the contrast agents - or microbubbles - used for molecular imaging and vasa vasorum detection," Jiang emphasised.

The prototype device has performed well in lab testing but the researchers say they are continuing to optimise the technology.

The paper was published in the journal IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.