Spatial Resolution of Attenuation Imaging

The attenuating properties of biological tissue are of
great importance in ultrasonic examination even though its anatomical
variability limits diagnostics effectiveness. We are currently developing a
technique for parametric imaging of attenuation and we intend to apply it for in
vivo characterization of tissue. The diagnostic usefulness of the proposed
technique crucially depends on the precision of the attenuation estimate and the
resolution of the parametric image. These two parameters are highly correlated,
since the resolution is reduced whenever averaging is used to minimize the
errors introduced by the random character of the backscatter. Here we report on
the results of numerical processing of both, simulated and recorded from a
tissue-mimicking phantom echoes. We have analyzed the parameters of the
estimation technique and examined their influence on the precision of the
attenuation estimate and on the parametric image resolution. The optimal
selection of attenuation image parameters depending on its intended diagnostic
use, was also considered.