Enhanced lesion visualization in image-guided noninvasive surgery with ultrasound phased arrays

We describe dual-mode ultrasound phased arrays for noninvasive image-guided surgical applications. In particular, we address the problem of real-time visualization of thermal lesion formation in the target (e.g., tumor) tissue using the therapeutic arrays. Post beamforming filter bank image reconstruction with nonlinear compounding is utilized to improve the lesion contrast in the (typically) very low-contrast ultrasound images. It is shown that the new image reconstruction algorithm leads to measurable improvement in lesion contrast on the order of 6-15 dB. This leads to significant improvement in lesion detectability and size estimation by standard segmentation techniques for speckle imagery. Experimental results strongly suggest that 2^nd harmonic imaging could play an important role in the enhancement of real-time lesion visualization.