Real-time ultrasound-guided high-intensity focused ultrasound therapy with enhanced visualization and reduced treatment time

We present a novel technique for synchronizing diagnostic ultrasound imaging and High-Intensity Focused Ultrasound (HIFU) therapy systems for real-time image-guided therapy that does not require any modification of a commercial imaging system. HIFU therapy with a duty cycle of 83% could be performed simultaneously with B-mode imaging by combining 5 image frames to remove HIFU interference in the entire field of view, with an overall frame rate of 11 frames/s. In vivo experiments in rabbit thigh muscle showed that the volume of HIFU-treated lesions increased by 342% (p < 0.01) when the duty cycle was increased from 50% to 95% for the same HIFU treatment times. The HIFU treatment time required at 90% duty cycle was 64% less ( p < 0.05) than that required at a 50% duty cycle to create lesions of the same volume.