Electromagnetic Wave-Induced Vectorial Thermoacoustic Bioimaging

Electromagnetic wave-induced thermoacoustic imaging (EM-TAI) holds great promise for disease diagnostics and treatments. Yet, the relevant imaging modalities are mostly focusing on the scalar quantities. Compared with scalar counterparts, the vectorial imaging carries extra information associated with wavelength and polarization of EM waves, as well as scales, textures, and complex environments of biotissues. In this article, we develop a unified mathematical formula to interpret both scalar and vectorial origination in EM-TAI and further utilize the classical mode theory, rigorous numerical approaches, and EM-TAI experiments to depict the qualitative and quantitative features of the vectorial information. This study may offer a new insight into the understanding of the scalar and vectorial bioimaging in EM-TAI and also makes an access to the identification of the ordered structure, safety inspection on thermal or nonthermal effect.