A study of acoustic source generation mechanism of Magnetoacoustic Tomography.
Magnetoacoustic Tomography (MAT) is a non-invasive imaging modality for electrical conductivity with good contrast and high spatial resolution. We have analyzed the acoustic source generation mechanism of MAT and presented its physical model, including the simulations and experiments in this paper. In MAT, acoustic sources are generated in a conductive object placed in a static magnetic field. Pulsed current is injected into the object and produces a Lorentz force due to the static magnetic filed. Acoustic vibration was excited by the Lorentz force, and hence, ultrasound waves propagate in all directions and are collected with transducers placed around the object. The conductivity image can then be reconstructed with acoustic waves using some reconstruction algorithms. Because the acoustic source generation mechanism of MAT is the key problem of forward and inverse problems, we analyzed the physical process of acoustic source generation and presented the acoustic dipole source model according to the Lorentz force imposed on the object. In addition, computer simulations and experiments were also conducted. The results of simulations applying an acoustic dipole source model are consistent with experimental results. This study has cardinal significance for the accurate algorithm of MAT and provides a methodology and reference for acoustic source problems.
Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, China; College of Radiology, Taishan Medical University, Taian 271016, China.
Shigang
S
Wang
Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, China.
Shunqi
S
Zhang
Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, China.
Ren
R
Ma
Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, China.
Tao
T
Yin
Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, China. Electronic address: lzpeng67@163.com.
Zhipeng
Z
Liu
D003198:Computer Simulation; D058266:Dielectric Spectroscopy / Q000379:methods*; D004553:Electric Conductivity; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D060526:Magnetic Fields; D008954:Models, Biological; D011874:Radiometry / Q000379:methods*; D014054:Tomography / Q000379:methods*
Acoustic source; Dipole; Functional imaging; Magneto-acoustic Tomography (MAT)