Photoacoustic Thermometry Imaging for High-Intensity Focused Ultrasound

高强度聚焦超声(HIFU)是一种非侵入性治疗方法，使用聚焦超声束对组织进行局部加热，直到细胞被摧毁。监测组织中的温度升高对于安全和准确地提供热疗是必不可少的。然而，现有的监测技术，例如磁共振成像，在时间分辨率和监测视野方面有很大的限制。在本项目中，将开发一种基于光声层析成像(PAT)的新型三维温度成像设备，以获取HIFU换能器产生的加热。光声测温的基础是Gruneisen参数的温度依赖性，它导致记录的光声信号幅度随温度的变化。为了能够将这项技术转化到临床环境中，需要定义良好、通用和稳定的体模材料。然后，这些可以用来评估光声测温在不同实验场景中的准确性、稳健性和适用性。因此，最初的项目目标集中在模型的开发上，而项目的目标将是开发一种基于实验室的实时圆柱形光声扫描系统，用于HIFU测温，并应用该系统来评估不同和适当规定的超声条件下HIFU换能器所产生的加热。

High-intensity focused ultrasound (HIFU) is a non-invasive therapy where a focused ultrasonic beam is used to locally heat tissue until the cells are destroyed. Monitoring temperature rise in tissue is essential for the safe and accurate delivery of thermal therapies. However, existing monitoring techniques, for example, Magnetic Resonance Imaging, have significant limitations regarding temporal resolution and the monitored field of view. In this project, a novel 3D temperature imaging device will be developed based on Photo-Acoustic Tomography (PAT) to access heating induced by HIFU transducers. The basic of photoacoustic thermometry lays in the temperature dependence of the Gruneisen parameter that leads to changes in the recorded photoacoustic signal amplitude with temperature. In order to allow the translation of this technique to a clinical setting, well-defined, versatile and stable phantom materials are required. These can then be used to assess the accuracy, robustness and applicability of photoacoustic thermometry in different experimental scenarios. Thus, the initial project objective focuses on phantom development, while the project aims will be to develop a lab-based real-time cylindrical photoacoustic scanning system for HIFU thermometry and apply the system to assess the heating induced by HIFU transducers under different and well-prescribed sonication conditions.