Noninvasive extraction of tissue conductivity distribution is important in brain imaging and cancer detection. Here we present an improved method that can accurately image tissue conductivity using tomographically measured microwave-induced thermoacoustic data. Our reconstruction algorithm is first tested using simulations, and then validated using tissue phantom experiments where saline-containing tubes are used as target(s) with various target sizes, positions and conductivities. The average error of reconstruction for the simulations is reduced from 4.87% to 1.38% compared with the previous algorithm. The experimental results obtained suggest that accurate quantitative thermoacoustic imaging would provide a potential tool for precision medicine.
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