ATTENUATION AND BACKSCATTER ESTIMATION USING VIDEO SIGNAL ANALYSIS APPLIED TO B-MODE IMAGES

Most methods for in vivo quantitation of ultrasound attenuation and ba ckscatter are not available clinically because they rely upon acquirin g and analyzing radio frequency (rf) echo signals. This paper describe s a technique to estimate ultrasound attenuation and backscatter from B-mode image data. The video signal analysis (VSA) technique utilizes images of a reference phantom, taken using the same instrument setting s used to record images from the patient or sample, to account for eff ects of the transducer beam, system gain and signal processing on imag e data. A 'gray-scale look-up table' is derived to convert image pixel value data within a region of interest to echo signal amplitudes rela tive to echo signals from the same depth in the reference phantom. The se relative echo levels enable estimates of attenuation and backscatte r in the region of interest. VSA was used to quantify acoustic propert ies of test phantoms using 3 different clinical scanners and various t ransducers. The level of agreement between results obtained with diffe rent ultrasound imaging systems was very good. VSA attenuation and bac kscatter levels also compare favorably with attenuation coefficients a nd backscatter coefficients obtained using rf analysis. (C) 1997 Dynam edia, Inc.