中国物理B ›› 2023, Vol. 32 ›› Issue (5): 54302-054302.doi: 10.1088/1674-1056/ac872a
Su Li(李粟)1,2, Guoqiang Liu(刘国强)2,3, Liang Guo(郭亮)1,†, Wenwei Zhang(张文伟)2, Chaosen Lu(卢朝森)4, and Hui Xia(夏慧)2,3,‡
Su Li(李粟)1,2, Guoqiang Liu(刘国强)2,3, Liang Guo(郭亮)1,†, Wenwei Zhang(张文伟)2, Chaosen Lu(卢朝森)4, and Hui Xia(夏慧)2,3,‡
摘要: Magneto-acoustic tomography with current injection (MAT-CI) is a type of hybrid imaging; under the excitation of the static magnetic field, the thermoacoustic effect and the Lorentz force effect will exist at the same time. Therefore, the detected signal is a mixed signal generated by the simultaneous action of the two effects, but the influence of excitation parameters on the two effects is different. In this paper, for objects with different conductivity, the proportion of thermoacoustic signal (TA) and magneto-acoustic signal (MA) in the mixed signal is quantitatively analyzed in terms of three aspects: the magnetic induction intensity, pulse excitation and injection current polarity. Experimental and simulation analyses show that the intensity ratio of MA to TA is not affected when the conductivity varies from 0.1 S/m to 1.5 S/m and other conditions remain unchanged. When the amplitude of the pulse excitation and the strength of the magnetic induction are different, the growth rates of MA and TA are different, which has a significant impact on the proportion of the two signals in the mixed signal. At the same time, due to the Lorentz force effect, MA is affected by the polarity of the injected current and the direction of the static magnetic field. The combination of the static magnetic field and the injected current can not only distinguish the two signals in the mixed signal, but also effectively enhance the intensity of the mixed signal and improve the quality of the reconstructed image.
中图分类号: (Physiological acoustics)