Experimental investigation of the acoustic nonlinearity parameter tomography for excised pathological biological tissues.

The acoustic nonlinearity parameter B/A tomography is proposed as a novel imaging method in this paper. By using this method, the B/A tomography for various kinds of normal and pathological porcine tissues in vitro, including eight kinds of diseased livers, four kinds of diseased kidney and one kind of diseased spleen, are studied. Results indicate that all diseased tissues with changes in tissue composition and structural features exhibit higher grey-scale (higher B/A values) than corresponding normal tissues. In addition, the acoustic nonlinearity parameter is more sensitive to pathological states than acoustic linear parameters. To make a comparison with the acoustic nonlinearity parameter tomography, the acoustic linear parameter images, including two B-scan images for two kinds of diseased specimens, are also presented. Results of this paper show that the acoustic nonlinearity parameter tomography may be a novel method for tissue characterization in ultrasonic medical diagnosis.