Improving large angle cone beam CT image reconstruction with practical supplementary information

Abstract

Single circle cone beam scan is simple and fast to execute and image reconstruction with the Feldkamp algorithm is efficient, thus it is widely employed in a number of major medical imaging modalities. Cone beam scanners employing large area flat panel detectors with 256 rows or more are expected to appear on the market in the next few years. The large number of rows allows the collection of a large quantity of data in a very short time, and thus the new generation of scanners will be suited for scanning dynamic objects. Because of its speed single circle scan will be ideal for such scans. In 3D angio systems employing C arms the popular scan mode is circular arc, which is less complete compared to single circle scan. It is well known that a single circle scan path with Feldkamp reconstruction does not yield complete information to reconstruct the object. There are missing Radon data located along the rotation axis and its neighborhood In this paper we investigate the improvement to lite single circle scan reconstruction images with the use of supplemental), information. In particular we study a supplementary line scan and a supplementary circle scan. We also discuss the use of other sources of supplementary information, including topogram and a priori information.