Tomography and 3D Imaging

Abstract

The word tomography derives from the Greek word tomos meaning section, so the process of tomography involves the generation of narrow sections through an object each made up of individual volume elements (voxels) with a cross section Δx × Δy and thickness, s, as shown in the paper. This is at best a noninvasive or minimally invasive process that is performed using sensors outside the object of interest. In many applications, sequences of two-dimensional (2D) slices are combined to produce a pseudo-three-dimensional (3D) image. The process, when applied to X-rays, is referred to as computed axial tomography (CAT or CT). Computed tomography only became feasible with the development of computer signal processing capabilities in the 1960s, but many of the basic principles were developed many years before that. In 1917, a mathematician, J. Radon, showed that the distribution of material or the material properties of an object can be determined if the integral values along any number of lines passing through a particular layer are known (Deans and Roderick 1983).