Estimation of threshold noise suppression algorithm in microwave induced thermoacoustic tomography

Microwave induced thermoacoustic (MITA) tomography is a promising technique in biomedical imaging. It results in both high contrast of the electrical parameter to the background media due to microwave stimulation and high resolution of the image due to thermoacoustic tomography. In this paper, we present an estimation of threshold noise suppression algorithm for MITA tomography. The imaging reconstruction procedure mainly includes three steps. Firstly, wavelet analysis is utilized to improve the signal to noise ratio (SNR) of the thermoacoustic signals and remove the zero drift. Secondly, time reversal mirror (TRM) technique is applied as the reconstruction algorithm. Thirdly, an estimation of the threshold noise suppression algorithm is implemented to further suppress the background noise. The validity of this estimative algorithm is investigated through a two-dimensional imaging experiment by an integrated prototype of MITA tomography system. The algorithm results in great improvements in reconstructed image.