title: Optimization-based image reconstruction from sparse-view data in offset-detector CBCT.
abstract: The field of view (FOV) of a cone-beam computed tomography (CBCT) unit in a single-photon emission computed tomography (SPECT)/CBCT system can be increased by offsetting the CBCT detector. Analytic-based algorithms have been developed for image reconstruction from data collected at a large number of densely sampled views in offset-detector CBCT. However, the radiation dose involved in a large number of projections can be of a health concern to the imaged subject. CBCT-imaging dose can be reduced by lowering the number of projections. As analytic-based algorithms are unlikely to reconstruct accurate images from sparse-view data, we investigate and characterize in the work optimization-based algorithms, including an adaptive steepest descent-weighted projection onto convex sets (ASD-WPOCS) algorithms, for image reconstruction from sparse-view data collected in offset-detector CBCT. Using simulated data and real data collected from a physical pelvis phantom and patient, we verify and characterize properties of the algorithms under study. Results of our study suggest that optimization-based algorithms such as ASD-WPOCS may be developed for yielding images of potential utility from a number of projections substantially smaller than those used currently in clinical SPECT/CBCT imaging, thus leading to a dose reduction in CBCT imaging.
authors.affiliation: Department of Radiology, The University of Chicago, Chicago, IL 60637, USA.
authors.forename: Junguo
authors.initials: J
authors.lastname: Bian
authors.forename: Jiong
authors.initials: J
authors.lastname: Wang
authors.forename: Xiao
authors.initials: X
authors.lastname: Han
authors.forename: Emil Y
authors.initials: EY
authors.lastname: Sidky
authors.forename: Lingxiong
authors.initials: L
authors.lastname: Shao
authors.forename: Xiaochuan
authors.initials: X
authors.lastname: Pan
mesh_terms: D000465:Algorithms; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D010388:Pelvis / Q000000981:diagnostic imaging; D019047:Phantoms, Imaging