Real-time adaptive array processing for medical ultrasound imaging.

Abstract

Over the last decade, ultrasonic phased arrays have been used routinely for real-time medical imaging. Because of the inhomogeneous nature of tissue, however, the size of arrays employed in these systems has been limited. In particular, very small numerical apertures are commonly used because of problems in maintaining phase coherence over large apertures. Recently, phase aberration correction methods have been explored for medical phased arrays permitting diffraction limited resolution from large apertures. In this talk, the principles of imaging with a sampled aperture will be briefly reviewed. Following this review, the use of adaptive signal processing methods for removal of phase aberration problems will be explored. In addition, a practical array system constructed to test the principles of real-time phase aberration correction will be presented. The talk will conclude with a discussion of the extension of these techniques to full two-dimensional apertures.