Characteristics of the spatial coherence function from backscattered ultrasound with phase aberration and reverberation clutter

Clutter is acoustic noise that significantly degrades ultrasound image quality, and often results from multiple reflections between tissue layers. There is currently little characterization of this complex phenomenon and how it depends on tissue structure. We demonstrate how clutter can be characterized by the spatial coherence of the backscattered echo signals received by the transducer. Spatial coherence is a measure of the similarity of the received echo as a function of inter-element spacing. The objective of this paper is to characterize the properties of the spatial coherence of backscattered ultrasound under realistic diagnostic imaging conditions, which include common image degrading effects such as phase aberration and reverberation clutter.