雙模聚焦超音波用於透顱被動式成像技術開發

Abstract

聚焦式超音波成為一種新興的醫學治療工具，可用於治療腦部疾病。利用球面聚焦相控陣列能將聚焦能量偏離幾何中心的優點來治療更大的治療區域。而現今用來監控治療的被動聲場影像(PAM)是利用兩個探頭來完成，一個負責發射聚焦能量，另一個則負責做能量訊號接收來繪製影像。但是在這兩個探頭之間無法有效的利用和共享，且對醫生來說不易進行手術治療。因此本篇使用雙模球面聚焦相控陣列實現診斷、被動聲場影像及透顱引導能力。並且為了能同時治療且診斷能量分布，本篇利用角譜法來加快計算能量分布的影像繪製，實現聲場分布影像實時的可視化。並利用壓克力材料和真實離體頭骨比較影像呈現和實際數據的精確性，影像繪製用時從90秒經由角譜法提升至0.87±0.10秒，根據上述結果，本論文的方法對於透顱聚焦相控超音波陣列聚焦點調控並提供能量影像用於聚焦監測有顯著的效益。

Focused ultrasound has emerged as a promising medical treatment tool for brain diseases. The use of a spherically focused phased array allows the focused energy to be steered away from the geometric center, enabling treatment of larger areas. However, the current passive acoustic mapping (PAM) for treatment monitoring relies on two separate transducers: one for emitting the focused energy and the other for receiving the energy signals to generate images. The lack of efficient utilization and sharing between these two transducers poses challenges for surgical interventions.Therefore, this study proposes the use of a dual-mode spherically focused phased array to achieve diagnostic imaging, passive acoustic mapping, and transcranial steering capabilities. To simultaneously treat and assess the energy distribution, an angular spectrum method is employed to accelerate the calculation of energy distribution images, achieving real-time visualization of acoustic field distribution. The accuracy of the image representation is compared with actual data using acrylic material and trans-human-cadaver samples. The image processing time is reduced from 90 seconds to 0.87±0.10 seconds using the angular spectrum method. Based on the above results, the method proposed in this paper exhibits significant benefits for focal point control and monitoring in transcranial focused ultrasound using phased array technology. It enables precise regulation of the focal point and provides energy imaging for focal monitoring.