Temperature Monitoring Using Zero-crossing Tracking Technique During Focused Ultrasound Thermal Therapy

摘要

This paper investigates the feasibility of using a zero-crossing tracking (ZCT) technique to monitor temperature changes during high intensity focused ultrasound (HIFU) thermal therapy. The ZCT technique tracks the shifts in the zero-crossing instants between the pre- and postheated A-lines to estimate the echoshifts caused by local temperature changes. Compared to the conventional cross-correlation (CCR) technique, ZCT does not require intensive computational loadings for correlation operations; hence, the computational efficiency could be improved. The parameters used, such as the size of the segment window, segment overlap and the window used to compute the echoshift gradient, could substantially affect the estimation results. With optimized parameters, the estimation errors for the peak temperature and the size of the hotspot could be less man 1℃ and 10%, respectively.