Tissue classification of arterial wall based on elasticity image

The phased tracking method was developed for measuring the minute change in thickness during one cardiac cycle and the elasticity of the arterial wall. By comparing elasticity images measured by the phased tracking method with the corresponding pathological images, the elasticity distribution for each tissue in the arterial wall was determined. We have already measured the elasticity distributions for lipids, fibrous tissues (mixture of smooth-muscle and collagen fiber), blood clots and calcified tissues. From these previous studies, it was found that arterial tissues can be classified into soft tissues (lipids and blood clots) and hard tissues (fibrous tissue and calcified tissue) on the basis of their elasticity. However, it was difficult to differentiate lipids from blood clots and also fibrous tissue from calcified tissue. In this study, we investigated how to improve the tissue classification of the arterial wall using statistical properties of the elasticity distribution of each tissue.