Biomedical applications of Terahertz Pulse Imaging

We present Terahertz Pulse Imaging (TPI) results of different human tissue types. Our results are part of an initial study to explore the potential of TPI for biomedical applications. A survey of different tissue types has demonstrated the various contrast mechanisms that are available in TPI, allowing different tissue types to be readily identified. This encourages the pursuit of further studies of TPI for a variety of biomedical applications. Measurements of human teeth have shown differences in the refractive index and absorption for enamel and dentine. Additionally, measurements of cross-sections have clearly demonstrated the ability of TPI to detect caries in the outer enamel layer and distinguish diseased tissue from other variations in enamel such as hypo-mineralisation. This is the first application of TPI to detecting diseased human tissue. Images of the enamel thickness and pulp chamber have been constructed using the difference in tissue properties. By analysis of the information contained in the time-domain at each pixel, the first image was constructed using time-of-flight. Further analysis of the absorption data permitted the position and shape of the pulp chamber to also be measured.