Monitoring of temperature and denaturation for hyperthermia therapy via a noninvasive, locally and temporarily resolved measurement of sound velocities

在癌症治疗中，局部热疗和烧蚀热疗法用于破坏肿瘤组织，是放疗和化疗的替代或补充。为了避免并发症和有效的应用，有必要监测温度分布和潜在的组织变性。这在神经或血管等脆弱结构的区域尤为重要。对于超声监测来说，纵波速度和横波速度的测量是非常合适的，因为纵波速度对温度的变化很敏感，而横波速度对组织结构的变化很敏感。这些基于超声波的测量提供了其他昂贵的温度监测的替代方案，例如MRI，因此在射频消融和HIFU治疗期间显示出有效的温度监测的巨大潜力。该项目的目的是延续上一个项目的成功成果。开发了一种纵波速度空间分辨测量方法。通过评估组织结构的散射回波，该过程无需在已知位置添加任何传感器或反射器即可工作。与2018年以来的其他文献方法相比，该方法在时空分辨率方面是唯一满足医学应用性能要求的方法。因此，这种创新的方法注定要产生声速和温度图，改善波束形成和纠正传统的b扫描。该方法的另一个优点是改进了横波弹性成像的性能。对于SWEI，横波测速精度显著提高，并实现了震源定位。在项目中，该方法的性能将在各种医学应用中得到证明，从而为临床领域铺平道路。为此，将解决以下任务：1，通过基于声场的传感器优化，将显著提高方法的准确性；2、将该方法应用于线性医疗阵列（从目前使用的环形阵列）；3、方法在Verasonic研究平台VANTAGE 64le上的实现；4、实现所启用的成像。在系统地检查了复杂的组织幻象后，与我们在SRH Wald-Klinikum Gera专门从事HIFU治疗的医疗合作伙伴合作，计划对离体样本进行后续测量。

In cancer therapy, local hyperthermia and ablative thermal procedures for the destruction of tumor tissue represent an alternative or supplement to radiotherapy and chemotherapy. To avoid complications and for an effective application, it is necessary to monitor temperature distribution and potential tissue denaturation. This is particularly important in the area of vulnerable structures such as nerves or blood vessels. For ultrasound-based monitoring, measurements of longitudinal wave velocity and transverse wave velocity are well suited, the former being sensitive to changes in temperature and the latter to changes in tissue structure. These ultrasound-based measurements provide an alternative to other costly temperature monitoring, such as MRI, and therefore show great potential for effective temperature monitoring during therapy with radiofrequency ablation and HIFU. The aim of the project is to continue the successful work from the previous project. A procedure for spatially resolved measurement of longitudinal wave velocity has been developed. By evaluating scattering echoes of tissue structures, the procedure works without any additional transducers or reflectors at known positions. Compared to other methods presented in the literature since 2018, the method is the only one that meets the performance requirements for medical applications in terms of spatial and temporal resolution. This innovative method is thus predestined for the generation of sound-velocity and temperature maps, for the improvement of beamforming and for the correction of conventional B-scans. Another benefit of the method is the improvement of the performance of shear wave elastography. For SWEI, the accuracy of transverse wave velocity determination is significantly increased and source localization is enabled. In the project, the performance of the method is to be demonstrated for a variety of medical applications, thus paving the way for the clinical realm. For this purpose, the following tasks will be addressed: 1, the accuracy of the method will be significantly increased by sound-field-based optimization of the transducers; 2, adapting the method for linear medical arrays (from the annular arrays used so far); 3, implementation of the method on Verasonic’s research platform VANTAGE 64 LE; und 4, the imaging enabled by the implementation. After systematic examination of complex tissue phantoms, subsequent measurements on ex-vivo samples are planned in cooperation with our medical partner specialized in HIFU treatment at the SRH Wald-Klinikum Gera.