谷川 俊一郎, 大栗 拓真

Shunichiro TANIGAWA, Takuma OGURI

GEヘルスケア・ジャパン株式会社超音波製品開発部

Ultrasound General Imaging and Primary Care, GE HealthCare Japan

キーワード : stiffness, shear wave, elastography, attenuation coefficient, diffuse liver disease

超音波による生体組織性状の新たな定量評価法として注目されている超音波shear wave elastographyと超音波減衰評価法の基礎について述べる．超音波shear wave elastographyは，臓器等内部に生じたせん断波の伝搬速度を測定し，臓器の硬さを評価する手法である．一方，超音波による減衰評価法（超音波減衰法）は，超音波が生体内を伝搬する過程で生体組織による吸収や散乱などによって生じた減衰を，超音波エコー信号から評価される減衰定数によって定量化する手法である．

This article describes the basis and principle of ultrasound shear wave elastography and ultrasound attenuation evaluation, which are attracting attention as new quantitative ultrasound measurement technologies for tissue characterization. Shear wave elastography is an imaging technique that quantifies tissue stiffness by measuring the speed of shear waves in tissue. This technique uses dynamic excitation to generate shear waves in the body. Ultrasound amplitude attenuates due to scattering and absorption, etc., while ultrasound waves propagate through tissue. Ultrasound attenuation measurement is a method to quantify ultrasound attenuation using an attenuation constant evaluated based on echo signals.