title: A novel hybrid reconstruction algorithm for first generation incoherent scatter CT (ISCT) of large objects with potential medical imaging applications.
abstract: This work presents a first generation incoherent scatter CT (ISCT) hybrid (analytic-iterative) reconstruction algorithm for accurate ρ{e}imaging of objects with clinically relevant sizes. The algorithm reconstructs quantitative images of ρ{e} within a few iterations, avoiding the challenges of optimization based reconstruction algorithms while addressing the limitations of current analytical algorithms. A 4π detector is conceptualized in order to address the issue of directional dependency and is then replaced with a ring of detectors which detect a constant fraction of the scattered photons. The ISCT algorithm corrects for the attenuation of photons using a limited number of iterations and filtered back projection (FBP) for image reconstruction. This results in a hybrid reconstruction algorithm that was tested with sinograms generated by Monte Carlo (MC) and analytical (AN) simulations. Results show that the ISCT algorithm is weakly dependent on the ρ{e} initial estimate. Simulation results show that the proposed algorithm reconstruct ρ{e} images with a mean error of -1% ± 3% for the AN model and from -6% to -8% for the MC model. Finally, the algorithm is capable of reconstructing qualitatively good images even in the presence of multiple scatter. The proposed algorithm would be suitable for in-vivo medical imaging as long as practical limitations can be addressed.
authors.affiliation: Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada. jorge.alpuche@cancercare.mb.ca
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Alpuche Aviles
authors.forename: Stephen
authors.initials: S
authors.lastname: Pistorius
authors.forename: Richard
authors.initials: R
authors.lastname: Gordon
authors.forename: Idris A
authors.initials: IA
authors.lastname: Elbakri
mesh_terms: D000465:Algorithms; D021621:Imaging, Three-Dimensional; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D017785:Photons; D011856:Radiographic Image Enhancement / Q000379:methods*; D012542:Scattering, Radiation; D014057:Tomography, X-Ray Computed / Q000379:methods*