Wavelet based local coherent tomography with an application in terahertz imaging

Abstract

Terahertz Computed Tomography (THz-CT) is a form of optical coherent tomography, which offers a promising approach for achieving non-invasive inspection of solid materials, with potentially numerous applications in industrial manufacturing and biomedical engineering. With traditional CT techniques such as X-ray tomography, full exposure data are needed to produce cross sectional images, even if the region of interest is small. For time-domain terahertz measurements, the requirement for full exposure data is impractical due to the slow measurement process. In this paper, we apply a wavelet-based algorithm to locally reconstruct THz-CT images with a significant reduction in the required measurements. The algorithm recovers an approximation of the region of interest from terahertz measurements within its vicinity, and thus improves the feasibility of using terahertz imaging to detect defects in solid materials and diagnose disease states for clinical practice. © Springer-Verlag Berlin Heidelberg 2007.