A local iterative reconstruction algorithm for planar integral data

Abstract

In this paper we develop an iterative algorithm for a set of parallel weighted or unweighted planar integrals of an object. The object is relative large and the entire object is not sufficiently measured, and the projections are truncated due to a small detector size. However, a small region-of-interest (ROI) is sufficiently measured. It is known that the Radon inversion formula is able to exactly reconstruct the ROI with truncated parallel unweighted planar integrals (i.e., the three-dimensional Radon transform). This local tomographic property is not found for line-integral measurements. The local tomography is usually not available when using iterative reconstruction methods because the forward-projection of the entire image of the object is impossible. This paper investigates an iterative algorithm that is able to accurately reconstruct the ROI using truncated planar integral data.