Magneto-thermal-acoustic imaging of magnetic nanoparticles with tissue structure imaging function

Magneto-thermal-acoustic imaging with magnetic nanoparticles (MNPs) is a novel medical imaging modality based on the thermoacoustic (TA) effect of MNPs. We proposed a new dual-modality imaging strategy that combines the TA and echo signals. Based on the synthetic aperture method, we used TA signals to image cancer tissues labeled with MNPs and applied echo signals to achieve tissue structure imaging. In the simulation, we constructed a breast cancer model and assumed that cancer tissue was labeled with MNPs. Under a limited field of view, the TA and echo signals were collected using a multi-element transducer array. By fusing the imaging results of the TA and echo signals, we obtained a boundary distribution map of the breast cancer model, and accurately located the tumor tissue. In this experiment, we built a multi-channel acquisition system. Pork tissue labeled with MNPs was used as the breast cancer phantom. We collected a total of 120 TA and echo signals at 1 mm intervals using a multi-element transducer array and faithfully imaged the boundary distribution map of the phantom. Compared with the traditional linear back projection method based on focused transducers, we demonstrated that the proposed method not only improves the lateral resolution of the image, but also makes accurate cancer identification easier. This provides a promising medical imaging technology for clinical applications.