Mechanical Modeling and Ultrasound Elasticity Imaging for Quantification of Hepatic Fibrosis

Abstract

To evaluate quantitatively the stage of chronic hepatitis with respect to fibrosis on the basis of ultrasound tissue elasticity imaging, we introduced a mechanical model of fibrosis progression and simulated the process by which hepatic fibrosis affects elasticity images and compared the results with those clinical data analysis. As a result, it was confirmed that even in diffuse diseases like chronic hepatitis, the patterns of elasticity images are related to fibrous structural changes caused by hepatic disease and can be used to derive features for quantitative evaluation of fibrosis stage. I. INTRODUCTION Ultrasound tissue elasticity imaging is a new modality for the visual assessment of tissue elasticity especially for cancer diagnosis. The first practical system was developed by us in 2003 and referred to as the Real-Time Tissue Elastography® (RTE). This technology has already been proved to be diagnostically valuable in detecting tumor of the breast, prostate and other organs.(1) We found that texture of elasticity image (strain) of chronic hepatitis becomes patchy pattern as liver fibrosis progress and could be categorized into the four stages.The purpose of this study is to evaluate fibrosis progression quantitatively using ultrasound tissue elasticity image with the aim of constituting a system for computer-aided diagnosis of chronic hepatitis. Then, we introduced a mechanical model of fibrosis progression and simulated the process that hepatic fibrosis affects elasticity images and compared clinical data analysis.