The soft tissue attenuation is an interesting parameter from medical point of view, because the value of attenuation coefficient is often related to the state of the tissue. Thus, the imaging of the attenuation coefficient distribution within the tissue could be a useful tool for ultrasonic medical diagnosis. The method of attenuation estimation based on tracking of the mean frequency changes in a backscattered signal is presented in this paper. The attenuation estimates are characterized by high variance due to stochastic character of the backscattered ultrasonic signal and some special methods must be added to data processing to improve the resulting images. The following paper presents the application of Spatial Compounding (SC), Frequency Compounding (FC) and the combination of both. The resulting parametric images are compared by means of root-mean-square errors. The results show that combined SC and FC techniques significantly improve the quality and accuracy of parametric images of attenuation distribution.
 BIGELOW T.A., MCFARLIN B.L., O'BRIEN W.D., OELZE M.L. (2008), In vivo ultrasonic attenuation slope estimates for detection cervical ripening in rats:Preliminary results, Journal of Acoustical Society of America, 123, 3, 1794-1800.
 COBBOLD R.S.C. (2007), Foundations of Biomedical Ultrasound, Oxford University Press.
 EVANS D.H., MCDICKEN W.N. (2000) Doppler Ultra sound: Physics, Instrumentation and Signal Processing, John Wiley & Sons Ltd.
 GOLYANDINA N., NEKRUTKIN V., AHIGLJAVSKY A. (2001), Analysis of time Series Structure: SSA and related techniques, Chapman & Hall/CRC.
 KLIMONDA Z., LITNIEWSKI J., NOWICKI A. (2009), Spatial Resolution of Attenuation Imaging, Archives of Acoustics, 34, 4, 461-470.
 KLIMONDA Z., LITNIEWSKI J., NOWICKI A. (2010), Tissue attenuation estimation from backscattered ultra sound using spatial compounding technique preliminary results, Archives of Acoustics, 35, 4, 643-651.
 KLIMONDA Z., LITNIEWSKI J., NOWICKI A. (2011), Synthetic Aperture technique applied to tissue attenuation imaging, Archives of Acoustics, 36, 4, 927-935.
 LAUGIER P., BERGER G., FINK M., PERRIN J. (1985), Specular reflector noise: effect and correction for in vivo attenuation estimation, Ultras. Imag., 7, 277-292.
 LU Z.F., ZAGZEBSKI J., LEE F.T. (1999), Ultrasound Backscatter and Attenuation in Human Liver With Diffuse Disease, Ultrasound in Med. & Biol., 25, 7, 1047-1054.
 MCFARLIN B.L., BIGELOW T.A., LAYBED Y., O'BRIEN W.D., OELZE M.L., ABRAMOWICZ J.S. (2010), Ultrasonic attenuation estimation of the pregnant cervix: a preliminary results, Ultrasound in Obstetrics and Gynecology, 36, 218-225.
 NIEMINEN H.J., SAARAKKALA S., LAASANEN M.S., HIRVONEN J., JURVELIN J.S., TOYRAS J. (2004), Ultrasound Attenuation in Normal and Spontaneously Degenerated Articular Cartilage, Ultrasound in Med. & Biol., 30, 4, 493-500.
 SAIJO Y., SASAKI H. (1996), High Frequency Acoustic Properties of Tumor Tissue, [in:] Ultrasonic Tissue Characterization, Dunn F., Tanaka M., Ohtsuki S., Saijo Y., 217-230 Springer-VerlagTokio, Hong-Kong.