Reduction of acoustic reverberation noise from therapeutic transducer for estimation of heat source distribution by acoustic radiation force imaging for high-intensity focused ultrasound treatment

Abstract High-intensity focused ultrasound (HIFU) is a noninvasive treatment that requires precise control of heat distribution to ensure safety and efficacy. Previous studies used a displacement measurement by acoustic radiation force (ARF) to predict the treated region before the treatment. However, measurement of displacement distribution immediately after the HIFU sonication is challenging due to interference from HIFU reverberation waves. In this study, three frequency filters—a high-pass filter, a combination of three notch filters, and a combination of high-pass and notch filters—were examined to reduce the HIFU reverberation components. In ex vivo experiments using chicken gizzard, the combination of high-pass and notch filters effectively attenuated noise at the fundamental (1 MHz), second harmonic (2 MHz), and third harmonic (3 MHz) frequencies, resulting in stable and accurate displacement measurements across a wide range of SNR conditions. These findings will contribute to improving the prediction accuracy of the treated region prior to the HIFU-based treatment.