Enhancement of SPECT reconstructions by means of coregistered MR data

P. Calvini, P. Vitali, F. Nobili, G. Rodriguez

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The diagnostic potential of brain SPECT imaging is limited by its low spatial resolution. Here an iterative reconstruction technique is proposed which is based on the Conjugate Gradient (CG) algorithm and offers the possibility of improving the spatial resolution of the SPECT activity map of a patient, provided that an MR scan of the same patient is available. The SPECT data are reconstructed twice. The first reconstruction is to permit an accurate coregistration of the MR image to the SPECT image. Then, the coregistered MR image is used as the starting point for the CG algorithm, which solves a "shifted problem". As the iterations proceed, the MR signal of low spatial frequency is replaced by the SPECT signal. However, the high spatial frequency anatomical details contained in the MR image are slowly destroyed by the SPECT projector-backprojector operator since they are nearly outside its range. They remain in the iterates and determine their spatial accuracy. The number of performed iterations and another parameter tune the MR bias on the SPECT reconstruction.

Original languageEnglish
Title of host publicationIEEE Nuclear Science Symposium and Medical Imaging Conference
EditorsD. Merelli, J. Surget, M. Ulma
Publication statusPublished - 2000
Event2000 IEEE Nuclear Science Symposium Conference Record - Lyon, France
Duration: Oct 15 2000Oct 20 2000


Other2000 IEEE Nuclear Science Symposium Conference Record

ASJC Scopus subject areas

  • Computer Vision and Pattern Recognition
  • Industrial and Manufacturing Engineering


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