Proposal of a parametric imaging method for quantitative diagnosis of liver fibrosis.
OBJECTIVE
Coming up with a quantitative diagnosis method for liver fibrosis using ultrasound would be highly significant. To permit tissue characterization using the characteristics of the echo signal such as power spectrum, texture parameters, local attenuation, and statistical characteristics, the relation between complicated scatterer structures and the echo signal must be understood.


METHODS
In this study, we analyzed the property of the echo amplitude envelope using computer-simulated scatterer models. These models mimicked various liver conditions to evaluate our quantitative parametric imaging methods. Statistical echo characteristics changed with the density of the heterogeneous scatterer buried in a speckle.


RESULTS
The new analysis method for a medium in which some tissues are embedded was proposed in consideration of analysis results from computer simulations. In the new method, it is possible to eliminate the influence of a cyst or veins and to detect the existence of fibers more clearly than in previous methods.
Research Center for Frontier Medical Engineering, Chiba University, 1-33 Yayoicho, Inage, Chiba, 263-8522, Japan. yamaguchi@faculty.chiba-u.jp.
Tadashi
T
Yamaguchi
Graduate School of Science and Technology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo, 152-8550, Japan.
Hiroyuki
H
Hachiya
Liver fibrosis; Probability density function; Scatterer density; Tissue characterization; Ultrasound