Terahertz pulsed imaging of liver cirrhosis

Terahertz Pulsed Imaging (TPItrade) is a coherent imaging technique that can be used to reveal the dielectric properties of samples. Liver cirrhosis is a common disease that can lead to hepatocellular carcinoma. It has been previously studied in the microwave region and the dielectric parameters of human cirrhotic liver were quantified. In this study, we characterized the refractive index and absorption coefficient of cirrhotic and normal liver tissue from laboratory rats in the terahertz region using TPI. We observed that both the refractive index and absorption coefficient of the cirrhotic liver samples were consistently higher than those of the normal samples from 0.2 to 1.5 THz. After the samples were fixed in formalin solution for 24 hours, differences in the refractive index and absorption coefficient were still seen. These results illustrate the sensitivity of TPI to soft tissue and provide motivation for developing TPI into a clinical imaging technique.