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，其中聚焦超声束用于局部加热组织，直到细胞被破坏。监测组织中的温升对于安全和准确地输送热治疗至关重要。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的视场方面具有显著的限制。本计画将开发一种新型的三维温度成像装置，以利用光声层析技术来量测高强度聚焦超声换能器所产生的热效应。光声测温的基础在于Gruneisen参数的温度依赖性，导致记录的光声信号幅度随温度的变化。为了将该技术转化为临床环境，需要定义明确、通用且稳定的体模材料。然后，这些可以用来评估在不同的实验场景中的光声测温的准确性，鲁棒性和适用性。因此，最初的项目目标侧重于体模开发，而该项目的目标将是开发一个基于实验室的实时圆柱形光声扫描系统，用于HIFU测温，并应用该系统评估HIFU换能器在不同和良好规定的超声条件下引起的加热。

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.