混合k空间经颅聚焦超声相位校正  

Transcranial focused ultrasound phase corrections using the hybrid k-space method

作　　者：闵尊清 何佳儒 吴灿文 程中文 曾吕明 陈燕 纪轩荣 MIN Zunqing;HE Jiaru;WU Canwen;CHENG Zhongwen;ZENG Lyuming;CHEN Yan;JI Xuanrong(State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment,School of Electromechanical Engineering,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]省部共建精密电子制造技术与装备国家重点实验室,广东工业大学机电工程学院,广州510006

出　　处：《应用声学》2024年第5期1093-1101,共9页Journal of Applied Acoustics

基　　金：广东省自然科学基金项目(2023A1515011620);国家自然科学基金项目(51975131,U2133213)。

摘　　要：经颅聚焦超声是一种非侵入性治疗方式,为脑功能性疾病的治疗提供了一种新思路,其常见的应用有血脑屏障打开、脑部肿瘤消融、神经调控等。由于颅骨的异质性,超声在传播过程中会产生畸变,需要一定的相位校正实现超声的聚焦。利用时间反转结合k空间伪谱可以实现对于非均匀的颅骨进行相位校正。然而,在相控聚焦过程中,同时提高相位校正的精度和减少计算的时间是一个矛盾的关系。该文提出伪谱法和角谱法相结合的混合k空间方法在较短时间内优化相位校正,k空间伪谱模拟非均匀的颅骨部分,角谱法模拟均匀的脑组织部分,并对经兔颅骨后的声场进行仿真与测试。结果表明,混合k空间和k空间相位校正方法得到焦点处的声压差和位置差较小,分别为3%和6%。在模型网格大小为310×310×300条件下,混合k空间相位校正方法的相位计算时间(14.98 min)与k空间方法(91.73 min)计算时间相比大幅降低,在脑超声治疗临床方面具有良好的应用前景。Transcranial focused ultrasound is a non-invasive treatment method that provides a new approach for the treatment of functional brain diseases.Common applications include opening the blood-brain barrier,ablation of brain tumors,and neuroregulation.Due to the heterogeneity of the skull,ultrasound undergoes distortion during propagation,requiring certain phase correction to achieve ultrasound focusing.By combining time reversal with k-space pseudospectra,phase correction can be achieved for non-uniformity skull structures.However,in the process of phase controlled focusing,there is a contradiction between improving the accuracy of phase correction and reducing computational time.This article proposes a hybrid k-space method that combines pseudo spectral method and angular spectral method to optimize phase correction in a short period of time.The k-space simulates non-uniform skull parts,while the angular spectral method simulates uniform brain tissue parts.The sound field after passing through the rabbit skull is simulated and tested.The results show that the mixed k-space and k-space phase correction methods result in smaller sound pressure and position differences at the focal point,which are 3%and 6%,respectively.The phase calculation time of the mixed k-space phase correction method can be reduced to 14.98 minutes compared with that of k-space phase correction method(91.73 minutes)under the same model grid size of 310×310×300,which indicates that the mixed k-space phase correction method has good application prospects in clinical brain ultrasound treatment.

关 键 词：聚焦超声 相位校正 角谱法 K空间 

分 类 号：R331[医药卫生—人体生理学]