Decorrelated compounding methods in synthetic transmit aperture ultrasound imaging and its application

Abstract

Speckles exist in most ultrasound images. They are generated due to the interference of the ultrasound waves scattered from multiple scattering particles in one resolution cell. Although they are very useful in many ultrasound applications, they limit the detection of low-contrast targets in a scattering medium. In conventional compounding, multiple correlated sub-images from various imaging apertures and frequency bandwidths are generated and then averaged incoherently to reduce the speckles. In this paper, we present our study on a method called Decorrelated Compounding to reduce speckles. In decorrelated compounding, a decorrelation procedure was applied to the correlated sub-images to further reduce speckle variance in synthetic transmit aperture (STA) ultrasound imaging. Decorrelated compounding was shown to improve the detectability of low-contrast lesions in terms of lesion signal-to-noise ratio (lSNR), visual detection, and statistical tests of the performance in detecting low-contrast lesions. The application of the proposed method to monitoring ultrasound thermal therapy and to measuring the attenuation coefficient will also be discussed.