Reconstructible volume for cone-beam CT with a reduced saddle trajectory

Saddle trajectory can be potentially useful for cardiac imaging and C-arm imaging. It can acquire cone-beam data sufficient for exact 3D image reconstruction. In last few years, a lot of effort has been devoted to reconstructing region of interest (ROI)-image from the data acquired with a full saddle scan. Recently we have proposed a reduced-scan approach in which data are collected only over an open portion of the saddle trajectory. Obviously, for an ROI-image reconstruction, the proposed reduced-scan approach can use less cone-beam data than what acquired in a full saddle scan. In this work, we have applied the chord-based algorithm and the extended polygon-based algorithm to reconstruct image for a reduced-scan saddle trajectory. Based upon the data requirements for both algorithms, we have determined the reconstructible ROI for a given reduced-scan saddle trajectory. Moreover, the computer-simulation studies have been presented to validate and evaluate the theoretically predicted reconstructible ROI by use of the chord-based and the extended polygon-based algorithms.