射频消融治疗中超声温度影像与弹性成像的可靠性研究

发布时间：2018-05-20 04:00

本文选题：射频消融 + 超声温度成像　；参考：《天津大学》2014年硕士论文

【摘要】：射频消融技术（Radiofrequency ablation，RFA）通过诱导热组织凝固性坏死达到治疗肿瘤的目的，已被认为是一种安全有效的微创治疗方法，目前在临床上得到广泛使用。成功的消融治疗有赖于射频消融区域的温度变化与坏死程度。超声成像成为目前医学影像中最常使用的监控手段，其成像方法包括温度成像和弹性成像。本课题通过射频消融离体猪肝实验探讨超声温度成像和弹性成像方法在不同功率射频消融监控下的适用性。本课题提出新的实验构架，选用若干块猪肝（长宽高=5cm4cm2.5cm）作为消融样本，在超声诊断仪实时监控下，分别于10w及50w功率下进行射频消融；加热过程中，将红外热成像仪放置于样本正前方，实时显示并记录组织在消融过程中组织表面实际的温度场分布图像，以此作为超声影像的参考标准。通过实验数据观测样本组织的超声温度图像和超声弹性成像。超声温度成像较常使用的有回波时移方法和基于逆散射能量变化的成像方法。本课题对两种方法算法上进行改进，通过实验数据分析表明基于回波时移的温度成像方法在低功率消融下，可准确显示消融区域，当温度升高至45℃以上，消融区域与实际不吻合；逆散射能量变化温度成像方法在高低功率下都表现出良好的一致性，比超声回波时移图像稳定性好。弹性成像方法选用临床上最常使用的压迫式弹性成像，，该方法在高功率下可以准确反映射频消融情况，在低功率消融下，由于温度上升范围有限，组织未完全坏死，弹性成像效果不理想。本课题首次综合考虑三种成像方法在高低功率下的适用性，研究表明超声温度成像方法中基于回波时移的成像存在只限于低功率下的射频消融的局限性，基于逆散射能量变化的成像方法在高低功率下都有较好的一致性；而弹性成像方法弥补了回波时移温度成像的不足，在高功率下表现出良好的优势，通过讨论三种成像方法为临床消融手术的超声监控提供了一条新的思路。
[Abstract]:Radiofrequency ablation (Radiofrequency ablation, RFA) has been considered as a safe and effective minimally invasive treatment for the purpose of treating tumor by inducing thermo tissue coagulation necrosis. It is widely used clinically. The successful ablation therapy depends on the temperature change and necrosis of the radiofrequency ablation area. For the most commonly used monitoring methods in medical imaging, the imaging methods include temperature imaging and elastic imaging. The applicability of ultrasonic temperature imaging and elastic imaging methods under different power radiofrequency ablation monitoring is discussed by radiofrequency ablation in vitro pig liver experiment.
In this subject, a new experimental framework is proposed. A number of pig liver (long and high =5cm4cm2.5cm) is selected as the ablation sample. Under the real-time monitoring of the ultrasonic diagnostic instrument, the radiofrequency ablation is performed under the power of 10W and 50W respectively. The infrared thermal imager is placed in front of the sample during the heating process, and the tissue surface of the tissue during the ablation process is displayed and recorded in real time. The actual temperature field distribution image is used as a reference standard for ultrasonic imaging. Ultrasonic temperature images and ultrasound elastography of tissue samples are observed through experimental data.
The ultrasonic temperature imaging is often used in the echo time shift method and the imaging method based on the inverse scattering energy change. This topic improves the algorithm of the two methods. Through the experimental data analysis, it is shown that the temperature imaging method based on the echo time shift can show the ablation region accurately under the low power ablation, when the temperature rises above 45 degrees centigrade. The fusion region does not coincide with the reality; the inverse scattering energy change temperature imaging method shows good consistency at high and low power, and the image is more stable than the ultrasonic echo. The elastic imaging method selects the most frequently used compression elastic imaging in clinical. This method can accurately reflect the radiofrequency ablation condition and low power in high power. Under the ablation rate, the elastography effect is not satisfactory due to the limited temperature rise and incomplete tissue necrosis.
The feasibility of the three imaging methods under high and low power is considered for the first time. The research shows that the imaging method based on echo time shift is limited to low power radiofrequency ablation, and the imaging method based on the inverse scattering energy change has good consistency at the high and low power rate. The method makes up the shortage of echo time shift temperature imaging, and shows good advantages under high power. By discussing three imaging methods, it provides a new idea for ultrasonic monitoring of clinical ablation operation.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R445.1

【相似文献】