Millisecond-Level Transient Temperature Monitoring Using an Ultra-Fast Response Thermocouple for Ultrasound-Induced Thermal Strain Imaging

Ultrasound-induced thermal strain imaging (US-TSI) is promising for vulnerable atherosclerosis plaque detection. To avoid arterial motion-induced artifacts, it is needed to induce a very fast temperature rise for US-TSI. Such a short time period for a negligible tissue motion is about 1/8th of a human cardiac cycle, which is corresponding to 75 ms – 125 ms. However, the current temperature monitoring techniques, such as infrared (IR) imaging and magnetic resonance (MR) thermometry, are known with difficulty in monitoring such rapid temperature rises inside biological tissue. Herein, this paper aims to use an ultra-fast response thermocouple to observe rapid temperature rise within 50 ms. Laser-induced thermal tests were conducted in air to verify the feasibility of transient temperature monitoring. Ultrasound-induced thermal tests were conducted in biological tissue to study the influence of various sonication parameters. Obvious transient temperature rises within 50 ms can be observed for both laser tests and tissue tests. The results manifest that the proposed method is capable of monitoring transient temperature rise in biological tissue for US- TSI.