Acoustic signal detection on magnetically mediated thermoacoustic imaging

摘要

Magnetically Mediated Thermoacoustic imaging (MMTAI) is a noninvasive imaging approach for electrical impedance. It collects ultrasound signals induced by thermal expansion to reconstruct the conductivity of the object with high spatial resolution and high contrast. Previously reported experimental results on MMTAI only were obtained from the high conductivity samples like the metal. In the study, the experimental system of MMTAI was established with low conductivity phantoms like biological tissues to validate the principle of MMTAI. Different geometrical salinity gel phantom models were designed with the shape of rectangle, triangle and ring, respectively. In the experiment, the gel phantoms were placed in an alternating magnetic field at radio frequency below 20MHz to induce electric field inside the gel phantoms, and thus, corresponding acoustic signals were produced by thermoacoustic effect, meanwhile acoustic signals were detected by the transducer. The experiments show that the acoustic signal can reflect the location information of the object. Furthermore, experiments may be improved to image the conductivity of the object on MMTAI.