IEEE Trans Biomed Eng. 2013 Oct;60(10):2751-9. doi: 10.1109/TBME.2013.2264484. Epub 2013 May 21.
A real-time dual-mode ultrasound array (DMUA) system for imaging and therapy is described. The system utilizes a concave (40-mm radius of curvature) 3.5 MHz, 32 element array, and modular multichannel transmitter/receiver. The system is capable of operating in a variety of imaging and therapy modes (on transmit) and continuous receive on all array elements even during high-power operation. A signal chain consisting of field-programmable gate arrays and graphical processing units is used to enable real time, software-defined beamforming and image formation. Imaging data, from quality assurance phantoms as well as in vivo small- and large-animal models, are presented and discussed. Corresponding images obtained using a temporally-synchronized and spatially-aligned diagnostic probe confirm the DMUA's ability to form anatomically-correct images with sufficient contrast in an extended field of view around its geometric center. In addition, high-frame rate DMUA data also demonstrate the feasibility of detection and localization of echo changes indicative of cavitation and/or tissue boiling during high-intensity focused ultrasound exposures with 45-50 dB dynamic range. The results also show that the axial and lateral resolution of the DMUA are consistent with its f(number) and bandwidth with well-behaved speckle cell characteristics. These results point the way to a theranostic DMUA system capable of quantitative imaging of tissue property changes with high specificity to lesion formation using focused ultrasound.
描述了一种用于成像和治疗的实时双模超声阵列 (DMUA) 系统。该系统采用凹面 (曲率半径 40mm) 3.5MHz、32 个元件的阵列和模块化多通道发射器/接收器。该系统能够在多种成像和治疗模式(发射时)下运行,并在高功率操作期间连续接收所有阵元的信号。一个由现场可编程门阵列和图形处理单元组成的信号链用于实现实时、软件定义的波束形成和图像形成。本文展示和讨论了来自质量保证体模以及体内小动物和大动物模型的成像数据。使用时间同步和空间对齐的诊断探头获得的相应图像证实了 DMUA 能够在其几何中心周围的扩展视场中形成具有足够对比度的解剖正确图像的能力。此外,高帧率 DMUA 数据还证明了在高强度聚焦超声暴露期间检测和定位指示空化和/或组织沸腾的回波变化的可行性,具有 45-50dB 的动态范围。结果还表明,DMUA 的轴向和侧向分辨率与其 f(number)和带宽一致,具有良好的斑点单元特性。这些结果为治疗诊断 DMUA 系统指明了方向,该系统能够使用聚焦超声对组织特性变化进行定量成像,具有对病变形成的高度特异性。