高能聚焦超音波燒灼肝腫瘤的數值研究

Abstract

肝癌是一種細胞異常變化的一種疾病， 它因不受控制而形成癌化腫瘤。 過去有許多文獻探討肝腫瘤以超音波產生熱方式治療， 卻少有文獻針對真正的肝臟外型做熱治療的研究， 本篇研究利用MRI取得肝臟外型後， 並在肝臟內部置入一動脈血管以及腫瘤， 將此三組織肝臟、腫瘤以及動脈血管做為研究對象。 利用聚焦型超音波換能器， 能夠在聚焦點產生高能量之特性， 將此能量打入腫瘤內部， 來觀察、分析腫瘤以及肝臟的溫度分布， 是否能有效使得腫瘤細胞因受高溫而死亡， 並且完整保護肝臟組織， 進而討論動脈血管的血液流動對於此手術過程所造成之影響。 並且將結合實驗來與吾人利用數值方法模擬之結果做一比對。

The study is aimed at predicting liver tumor temperature during thermal ablation using acoustics-thermal-fluid coupling model. The Rayleigh-Sommerfeld diffraction equation for HIFU(High-Intensity Focused Ultrasound) takes into account the wave distortion due to the finite-amplitude propagation. The nonlinear hemodynamic equations are also involved in the simulation domain that contains hepatic tissue domain, where homogenization dominates in perfusion, and vascular domain, where convective cooling is essential. Pennes Bioheat equation takes into account the thermal conduction with two heat sinks to account for tissue perfusion and forced convection-induced cooling. Acoustic streaming is also included in the numerical study. This article also designs a measurement to compare.