title: Multichannel algorithm for fast 3D reconstruction.
abstract: Some recent medical imaging applications such as functional imaging (PET and SPECT) or interventional imaging (CT fluoroscopy) involve increasing amounts of data. In order to reduce the image reconstruction time, we develop a new fast 3D reconstruction algorithm based on a divide and conquer approach. The proposed multichannel algorithm performs an indirect frequential subband decomposition of the image f to be reconstructed (f = sigma fj) through the filtering of the projections Rf. The subband images fj are reconstructed on a downsampled grid without information suppression. In order to reduce the computation time, we do not backproject the null filtered projections and we downsample the number of projections according to the Shannon conditions associated with the subband image. Our algorithm is based on filtering and backprojection operators. Using the same algorithms for these basic operators, our approach is three and a half times faster than a classical FBP algorithm for a 2D image 512 x 512 and six times faster for a 3D image 32 x 512 x 512.
authors.affiliation: Laboratoire d'Electronique et de Technologie de l'Information (LETI), Département Systèmes pour l'Information et la Santé (DSIS), Direction de la Recherche Technologique (DRT). Commissariat à l'Energie Atomique (CEA), Grenoble, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rodet
authors.forename: Pierre
authors.initials: P
authors.lastname: Grangeat
authors.forename: Laurent
authors.initials: L
authors.lastname: Desbat
mesh_terms: D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging*; D005471:Fluoroscopy / Q000379:methods; D005583:Fourier Analysis; D007089:Image Enhancement / Q000379:methods; D019047:Phantoms, Imaging; D011786:Quality Control; D011856:Radiographic Image Enhancement / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D014055:Tomography, Emission-Computed / Q000379:methods