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，用于破坏肿瘤组织的局部热疗和消融热程序代表了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领域尤为重要。对于基于超声的监测，纵波速度和横波速度的测量非常适合，前者对温度的变化敏感，后者对组织结构的变化敏感。 这些基于超声的测量为其他昂贵的温度监测（如MRI）提供了替代方案，因此在射频消融和HIFU治疗期间显示出有效温度监测的巨大潜力。该项目的目的是继续从以前的项目的成功工作。本文提出了一种空间分辨的纵波速度测量方法。 通过评估组织结构的散射回波，该过程在已知位置处不需要任何额外的换能器或反射器。与自2018年以来文献中提出的其他方法相比，该方法是唯一一种在空间和时间分辨率方面满足医疗应用性能要求的方法。 因此，这种创新的方法是注定的声速和温度图的生成，波束形成的改进和传统的B扫描的校正。 该方法的另一个优点是提高了剪切波弹性成像的性能。对于SWEI，横波速度确定的准确性显着提高，并使源定位。在该项目中，该方法的性能将被证明用于各种医疗应用，从而为临床领域铺平道路。为此，将解决以下任务：1，通过基于声场的换能器优化，将显著提高该方法的准确性; 2，将该方法用于线性医疗阵列（从迄今为止使用的环形阵列）; 3，在Verasonic的研究平台Vantage 64 LE上实施该方法; 4，通过实施实现成像。在对复杂组织模型进行系统检查后，计划与我们在SRH Wald-Klinikum Gera专门从事HIFU治疗的医疗合作伙伴合作，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.