Method research on magneto-acoustic-electric tomography using liquid conductor
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Updated: Jan 18, 2026
Ultrasound Velocity Measurement in a Liquid Metal Electrode
Published on: August 5, 2015
Yuheng Wang1, Junjie Lin1, Yi Wu1
1State Key Laboratory of Advanced Medical Materials and Devices, Institute of Biomedical Engineering, Tianjin Institutes of Health Science, Chinese Academy of Medical Science & Peking Union Medical College, Tianjin, China.
Background:
Magneto-acoustic-electric tomography (MAET) has the potential for noninvasive imaging of tissue electrical properties, which is valuable for early tumor detection and detection of electric current within tissues. However, it is plagued by challenges like low signal-to-noise ratio (SNR) and long imaging time, restricting its practical applications.
Purpose:
This study aims to address these issues by introducing a novel method. A gallium-based liquid conductor (Ga67In20.5Sn12.5) with high conductivity is combined with M-sequence coded excitation in MAET.
Methods:
The performance of Barker code and M-sequence in improving MAET SNR was compared and analyzed through simulation. To validate the simulation results of coded excitation and compare and analyze electrode placement methods in actual complex scenarios, a gel-liquid conductor model was prepared. Paired t-test was used to analyze the difference in SNR. The experiment used a 0.3T magnetic field and an 80 mm focused ultrasound transducer, and the signal was compressed through matched filtering, followed by signal reconstruction in B-scan mode. Finally, 31bit M-sequence was used to reconstruct liquid conductor MAET images of mice in vivo.
Results:
Simulation results show that the M-sequence offers better SNR enhancement compared to Barker code, especially with longer bit lengths. Experimentally, the 31bit M-sequence excitation increases the peak SNR (PSNR) by approximately 13 dB compared to single-pulse excitation, significantly better than that of 13bit Barker code. It also maintains a stable 1 MHz central frequency across different conductor thicknesses and coding bit. In complex geometries, M-sequence shows clearer boundaries than 13bit Barker code in electrode placement studies. Moreover, in vivo imaging successfully visualizes the liquid conductor in mouse tissues without adverse effects.
Conclusions:
This research presents an effective MAET framework. By using the combination of a liquid conductor and M-sequence coded excitation, it enhances the SNR, speeds up imaging, and improves the reconstruction quality, providing a foundational basis for clinical translation.
