WIAS Preprint No. 1119, (2006)

Accurate localization of brain activity in presurgical fMRI by structure adaptive smoothing


  • Tabelow, Karsten
    ORCID: 0000-0003-1274-9951
  • Polzehl, Jörg
    ORCID: 0000-0001-7471-2658
  • Uluğ, Aziz M.
  • Dyke, Jonathan P.
  • Watts, Richard
  • Heier, Linda A.
  • Voss, Henning U.

2010 Mathematics Subject Classification

  • 62P10 92C55 62G05 62G10


  • functional MRI, spatially adaptive smoothing, signal detection, presurgical planning




An important problem of the analysis of fMRI experiments is to achieve some noise reduction of the data without blurring the shape of the activation areas. As a novel solution to this problem, the Propagation-Separation approach (PS), a structure adaptive smoothing method, has been proposed recently. PS adapts to different shapes of activation areas by generating a spatial structure corresponding to similarities and differences between time series in adjacent locations. In this paper we demonstrate how this method results in more accurate localization of brain activity. First, it is shown in numerical simulations that PS is superior over Gaussian smoothing with respect to the accurate description of the shape of activation clusters and and results in less false detections. Second, in a study of 37 presurgical planning cases we found that PS and Gaussian smoothing often yield different results, and we present examples showing aspects of the superiority of PS as applied to presurgical planning.

Appeared in

  • IEEE Trans. Med. Imaging, 27 (2008) pp. 531--537.

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