High Intensity Focused Ultrasound Therapy Combined with 3d Real Time Tracking Motion System

For optimal treatment conditions, patient motion, particularly respiratory motion, must be monitored and corrected during HIFU treatments. We propose here a new generation of multi-channel HIFU systems able to track and correct in real-time the 3D motion of tissues. It is based on an accurate ultrasonic speckle tracking method for both following and compensating the motion of the tumor. The displacement estimation is based on 1D cross-correlation of the RF signals at two different times. The complete 3D motion estimation requires using at least three sub-apertures on a large phased array. The motion tracking sequences are interleaved with HIFU sequences at a high repetition rate. This provides a feedback for the HIFU beam steering correction and HIFU experiments combined with 3D real-time motion correction are successfully performed in moving fresh tissues samples.