Novel Ultrasound-Induced Thermal Strain Imaging

University of Pittsburgh, North Carolina State University, and an industrial partner Blatek Industries, Inc., have developed a novel ultrasound-induced thermal strain imaging (US-TSI) device. Using dual heat transducer arrays produced from a hard piezoelectric material it is possible to increase the temperature of blood vessels or other biological material by 2 °C within 50 ms. This novel strategy could allow for non-invasive, accurate, monitoring of lipids in atherosclerosis plaques identifying vulnerable plaques that lead to sudden cardiac death or acute ischemic stroke. 

US-TSI, where images based on changes in the speed of sound because of temperature changes in tissue are generated, has the potential to improve diagnosis and monitoring in atherosclerosis. A novel device to facilitate the use of US-TSI in humans has been developed and for the first time successfully demonstrated millisecond–level heating and temperature monitoring.

Description

Atherosclerosis, the buildup of plaque in the inner lining of an artery leading to its thickening or hardening, contributes to nearly 20 million deaths globally each year. Early diagnosis is key, but atherosclerosis is one of the most complex cardiovascular diseases (CVDs) to diagnosis and there is a great clinical need for new diagnostic techniques. Ultrasound-induced thermal strain imaging (US-TSI), is a technique where body tissue is heated by ultrasound and differential changes in sound speed can be used to identify atherosclerosis plaques. This technique can also identify plaques with a higher proportion of lipids present which may be prone to rupture. Early identification of these plaques could prevent patients experiencing coronary thrombosis or other catastrophic cardiovascular events.

Applications

• Atherosclerotic disease
• Cardiovascular disease

Advantages

US-TSI has shown promise in animal research settings. The use of US-TSI has been limited in humans as no device that could allow for a very fast temperature rise in a large volume (i.e., carotid artery) with acoustic power under the FDA safety limit exists. Fast temperature increases are required to avoid physiological motion artifacts. This novel device is designed with a heating transducer consisting of dual 1.5D arrays placed either side of an imaging array and can heat blood vessels by 2 C within 50 ms. This rapid heating process using ultrasound reduces the risk of heat loss through blood flow prior to imaging, limiting the risk of interference and enhancing the image quality of blood vessels containing plaques.

Invention Readiness

A prototype probe suitable for use in the carotid artery was produced. In vivo and in vitro studies demonstrated this device could increase the temperature of body tissue rapidly by 2C. Further work is required to understand performance in clinically relevant samples, perform a pilot human study and to optimize the probe and usage protocol.

IP Status

https://patents.google.com/patent/WO2023039178A2