Terahertz pulsed imaging of frozen biological tissues

Recently, terahertz wave imaging has been shown to have potential in medical and biological applications. However, absorption by liquid water in tissues hinders the measurement of thick samples. In this study, porcine tissue was frozen to temperatures below -33 degrees C to prevent this absorption. Consequently, the striated muscle and adipose tissue could be clearly distinguished in the terahertz time-domain spectra owing to the difference in absorbance values and refractive indices. We demonstrated two-dimensional map of absorbance and terahertz pulse delay, which clearly shows the spatial distribution of the tissues.