Polarization effects in thermoacoustic CT of biologic tissue at 434 MHz

Thermoacoustic image contrast is dependent on the dielectric and thermoacoustic properties of the tissue being imaged, its spatial distribution, and the polarization of the incident microwave radiation. We have designed and constructed a thermoacoustic computed tomography (TCT) test platform to study these effects in phantoms and biologic tissue (e.g., beefsteak and mice). Our results indicate that muscle and fat are easily differentiated, but the relative thermoacoustic absorption is strongly dependent upon the polarization angle of the microwave radiation and the morphology of fat and muscle tissues.