Treatable focal region modulated by double excitation signal superimposition to realize platform temperature distribution during transcranial brain tumor therapy with high-intensity focused ultrasound

• 来源期刊: 中国物理B（英文版）
• 关键词: high-intensity focused ultrasound (HIFU) transcranial therapy double excitation signal superim-position temperature modulation of focal region
• 年，卷（期）: 2018,（7）
• 页码范围: 670-680
• 页数: 11页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/7/078701

摘要

Recently, the phase compensation technique has allowed the ultrasound to propagate through the skull and focus into the brain. However, the temperature evolution during treatment is hard to control to achieve effective treatment and avoid over-high temperature. Proposed in this paper is a method to modulate the temperature distribution in the focal region. It superimposes two signals which focus on two preset different targets with a certain distance. Then the temperature distribution is modulated by changing triggering time delay and amplitudes of the two signals. The simulation model is established based on an 82-element transducer and computed tomography (CT) data of a volunteer's head. A finite-difference time-domain (FDTD) method is used to calculate the temperature distributions. The results show that when the distances between the two targets respectively are 7.5–12.5 mm on the acoustic axis and 2.0–3.0 mm in the direction perpendicular to the acoustic axis, a focal region with a uniform temperature distribution (64–65 ℃) can be created. Moreover, the volume of the focal region formed by one irradiation can be adjusted (26.8–266.7 mm3) along with the uniform temperature distribution. This method may ensure the safety and efficacy of HIFU brain tumor therapy.