組織構造変化に基づく超音波肝病変画像シミュレーション手法の検討

摘要

For quantitative diagnosis of hepatic disease, it is important to examine the relationship between ultrasonic image and liver tissue. However, a basic quantitative investigation of the useful diagnosis information is difficult because of the interference of the tissue structure such as a large blood vessel. So we have proposed a model of the scatterer distribution in hepatic lesion, and studied in detail the relationship between tissue and ultrasound images that were created by simulated ultrasonic echo signal from distributed scatterers. In this report, we present a new three-dimensional model of the scatterer distribution in diseased liver. We examine model parameters to construct the tissue structure of various hepatic lesions. Using the new model, three-dimensional scatterer distribution in various hepatic lesions was expressed well. We were able to get the simulated ultrasonic image in which was reflected the three dimensional tissue structure.%肝病変の定量診断のためには，肝臓組織の変化と画像変化の関係について検討することが重要となる．しかし，実画像には大きな血管などの組織情報が混入し定量診断に有益な情報を検討することが困難である．そこでわれわれは，肝病変の進行に伴う散乱体分布変化の表現法を提案し，その散乱体分布に対し超音波を照射することで作成した超音波断層画像と生体組織の関係を詳細に検討してきた．本報告ではこれまで提案してきた組織変化のモデルを改良し，種々の肝病変を表現するために必要なパラメータについて検討を行った．種々の病変の進行に伴う肝臓の三次元散乱体分布の変化が良好に再現し，二次元構造を反映したシミュレーション画像を得ることができた．