Thermoacoustic Tomography of Rat Brain Under 1.3GHz Microwave Excitation

Microwave-induced thermoacoustic tomography (TAT) is a novel noninvasive imaging technique, which combines the advantages of deep penetration depth /high contrast of microwave imaging and high resolution of ultrasound imaging. Previous studies on TAT of brain mainly were performed under the 3GHz microwave excitation frequency. Due to the dielectric property of tissue changes with the microwave excitation frequency, different frequencies of microwave excitation can result in different TAT imaging contrast. In this study, we proposed to use 1.3GHz microwave excitation to perform TAT of rat brain, and compared it with TAT images under 3GHz microwave excitation. The results showed that TAT images under 1.3GHz and 3GHz microwave excitation were in good agreement with the anatomical structures. Compared to the TAT images obtained by 3GHz microwave illumination, the TAT images obtained by 1.3GHz microwave illumination provided different contrasts and rich detail information. The preliminary evaluation provides the foundation for subsequent research on multi-frequency TAT of brain disease detection.