A new study shows that health care providers can potentially determine the risk of strokes and heart attacks through ultrasound. By using the imaging exam to analyze the plaques in a patient's blood vessels, researchers from Lund University in Sweden have shown they can identify patients at risk of developing acute cardiovascular diseases.

“We have shown that there is a strong correlation between changes in the centre frequency and the size of the reflecting particles. The more harmful substances, the greater the so-called frequency shift,” said Tobias Erlöv in a statement. He is currently conducting research at the university's Department of Biomedical Engineering.

More than half a decade ago, researchers at Lund University wanted to determine an easier way to recognize unstable plaques, where in worst-case scenarios, rupture can cause heart attacks or strokes.
Erlöv, at that time, discovered a mathematical calculation that can be used to interpret ultrasound signals, which helps figure out whether the plaque in the carotid artery is harmful or not.

Vascular surgery is only performed if there are too many large plaques, disrupting blood flow in the arteries. However, determining an unstable plaque cannot be done by simply studying flow rates and plaque sizes, knowing the type of cell concerned is more important, according to the study.

Harmless plaques consist of connective tissue and smooth muscle cells while harmful plaques consist of fat and macrophages. Unstable plaques can also involve bleeding.

Before this new ultrasound innovation can be used in health care facilities, more studies will have to be conducted. A large European research collaboration, Summit, has a study already underway with 1,500 patients.

In the future, ultrasound scans of the carotid artery may lead to the ability to perform surgery at an earlier stage in some cases, and to avoid surgery completely in others. It can also be used to follow up on patients after procedures in which the plaque was removed.

“Ultrasound enables you to screen a larger population, and that in turn means that life-threatening cardiovascular diseases can be detected at an earlier stage,” said Magnus Cinthio, senior lecturer in biomedical engineering and one of the researchers leading the work.

“Another advantage is that the method is inexpensive and completely harmless to patients,” added Erlöv.

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