Functional Connectivity

Tractographic functional connectivity based on diffusion-weighted fMRI.

Detection of functional connectivity requires two different datasets: Diffusion Tensor Images (DTI) data as a base for tractograpy and fMRI maps to serve as seed points for the functional connectivity analysis. FMRI maps are commonly calculated from Blood Oxygen Level Dependant (BOLD) or perfusion sensitive functional data. Due to the different deformation characteristics between these techniques and DTI, the connectivity analysis often fails or gives unreliable results. Diffusion Weighted Imaging (DWI) based functional maps have a identical deformation characteristics than the DTI data. Thus, we will combine these two imaging techniques for functional connectivity.

Functional connectivity studies based on fiber tracking often lack on the choice of appropriate seed points. The goal of this project is to establish a robust method in generating functional seed points for fiber tracking algorithms based on functional Apparent Diffusion Coefficient (ADC) maps.

Methods

• MR: 3T scanner , DWI, DTI, fMRI
• Paradigm: visual perception and motor
• Subjects: Healthy adults and children

Tractographic reconstruction of a DTI dataset of a 9 year old girl displaying the sensori-motor fiber tracts (projection fibres) from medulla to subcortical white matter.

Collaborations

Prof. Jürgen Hennig and Dr. Kamil Il’yasov, Medical Physics, Department of Diagnostic Radiology, University Hospital Freiburg, Germany

Contact

Dr. Malek Makki
malek.makkikispi.uzh.ch

Prof. Dr. Ernst Martin
ernst.martinkispi.uzh.ch

Former collaborators

Dr. Thomas Loenneker

Project duration

ongoing

Publications

Imfeld A, Oechslin M, Meyer M, Loenneker T, Jäncke L (2009). White matter plasticity in the corticospinal tract of musicians: a diffusion tensor imaging study. Neuroimage, 46(3), 600-607.

Zamboni SL, Loenneker T, Boltshauser E, Martin E, Il’yasov KA (2007). Contribution of diffusion tensor MR imaging in detecting cerebral microstructural changes in adults with neurofibromatosis type 1. AJNR Am J Neuroradiol, 28(4): 773-776.

Kreher BW, Schneider JF, Mader I, Martin E, Hennig J, Il’yasov KA (2005). Multitensor approach for analysis and tracking of complex fiber configurations. Magn Reson Med, 54(5): 1216-1225.

Schneider JF, Il’yasov KA, Hennig J, Martin E (2004). Fast quantitative diffusion-tensor imaging of cerebral white matter from the neonatal period to adolescence. Neuroradiology, 46(4): 258-266.

Schneider JF, Il’yasov KA, Boltshauser E, Hennig J, Martin E (2003). Diffusion tensor imaging in cases of adrenoleukodystrophy: preliminary experience as a marker for early demyelination? AJNR AM J Neuroradiol, 24(5): 819-824.