Signal processing in microwave-induced thermoacoustic tomography
Microwave-induced thermoacoustic tomography was explored to image biological tissues. Short microwave pulses irradiated tissues to generate acoustic waves by thermoelastic expansion. The microwave-induced thermoacoustic waves were detected with a focused ultrasonic transducer to obtain two-dimensional tomographic images of biological tissues. The dependence of the axial and the lateral resolutions on the spectra of the signals was studied. A self-adaptive filter was applied to the temporal piezoelectric signals from the transducer to increase the weight of the high-frequency components, which improved the lateral resolution, and to broaden the spectrum of the signal, which enhanced the axial resolution.
Additional Information© 2001 Society of Photo-Optical Instrumentation Engineers (SPIE). We thank G. Ku for experimental assistance. This project was sponsored in part by the U.S. Army Medical Research and Materiel Command Grant No. DAMD17-00-1-0455, the National Institutes of Health Grants No. R01 CA71980 and No. R21 CA83760, the National Science Foundation Grant No. BES-9734491, and Texas Higher Education Coordinating Board Grant No. ARP 000512-0123-1999.
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