title: Eigenvector decomposition of full-spectrum x-ray computed tomography.
abstract: Energy-discriminated x-ray computed tomography (CT) data were projected onto a set of basis functions to suppress the noise in filtered back-projection (FBP) reconstructions. The x-ray CT data were acquired using a novel x-ray system which incorporated a single-pixel photon-counting x-ray detector to measure the x-ray spectrum for each projection ray. A matrix of the spectral response of different materials was decomposed using eigenvalue decomposition to form the basis functions. Projection of FBP onto basis functions created a de facto image segmentation of multiple contrast agents. Final reconstructions showed significant noise suppression while preserving important energy-axis data. The noise suppression was demonstrated by a marked improvement in the signal-to-noise ratio (SNR) along the energy axis for multiple regions of interest in the reconstructed images. Basis functions used on a more coarsely sampled energy axis still showed an improved SNR. We conclude that the noise-resolution trade off along the energy axis was significantly improved using the eigenvalue decomposition basis functions.
authors.affiliation: Joint Department of Biomedical Engineering, North Carolina State University and The University of North Carolina at Chapel Hill, Campus Box 7115, Raleigh, NC 27695-7115, USA. gonzalib@gmail.com
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Gonzales
authors.forename: David S
authors.initials: DS
authors.lastname: Lalush
mesh_terms: D000042:Absorption; D000465:Algorithms; D003287:Contrast Media / Q000494:pharmacology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015233:Models, Statistical; D019047:Phantoms, Imaging; D017785:Photons; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D012542:Scattering, Radiation; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014965:X-Rays
chemical_list: D003287:Contrast Media