S波段微波热致超声成像系统研究

微波热致超声成像技术通过向物体发射微波脉冲, 导致物体吸收电磁波温度迅速升高, 产生瞬时压力波, 从而激发产生超声波信号, 通过传感器对产生的超声波信号进行采集并成像, 最终还原了反映物体吸收电磁波能量特性的图像, 由于此方法兼具了微波成像的高对比性和超声成像的高分辨率特点, 理论上验证了热声成像技术对早期乳腺肿瘤检测的可行性. 本实验兼顾系统成像深度和分辨率, 采用S波段的微波脉冲信号源对物体进行辐射, 利用圆形扫描方式对待测物体进行检测, 同时为了更好的验证成像性能, 本实验同时使用了肿瘤仿体及实际生物组织进行成像实验. 通过实验分析, 验证了该系统对肿瘤仿体和生物组织检测的有效性, 以及系统的高分辨率和高对比度特性, 为早期乳房肿瘤检测提供了进一步的理论支撑.

S-band microwave-induced thermo-acoustic tomography system

The technology of microwave-induced thermo-acoustic tomography that transmits electromagnetic wave pulses to the object and makes it absorb energy, can cause a rapid temperature rise in it. At the same time, a pressure wave will be generated instantaneouly, corresponding to generating an ultrasonic signal which can be detected by an ultrasonic sensor. After the ultrasonic signal is sampled and an image reconstructed, the image can reflect the characteristics of the electromagnetic energy absorbed by the object. The method combines a microwave imaging of high contrast and high resolution ultrasound imaging characteristics, hence verifies theoretically the feasibility of the thermo-acoustic imaging techniques for early breast cancer detection. In this study, we use S-band microwave pulse radiation source to radiate the biological tissue, and also make use of the circling mechanical motion systems to scan the tissue. In order to verify the imaging performance of the simulation experiments, we use both tumors, body and actual biological tissue as the samples of the experiments. The imaging reconstruction and comparative analysis can verify that the experimental system detects and distinguishes the tumor phantoms and the real biological tissue effectively. Results of the performance of high-resolution images and high contrast by the methods can provide further theoretical support for early detecting of breast cancer.