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Reconstruction of Neuronal pathways by Diffusion-Weighted MRI |
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Fibre tracking is a method for the reconstruction of neuronal pathways using measurements of the anisotropic diffusion of water molecules in the fibrous structure of white matter. Such information is made available by a recent advances in magnetic resonance imaging (MRI). Fiber tracking promises a high impact in fundamental neuroscience and its clinical applications.
Global Reconstruction of Neuronal Pathways
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Fiber tracking approaches can be divided into two groups: local and global methods. Local methods construct fibers independently path-by-path, the fibers do not influence each other. The reconstruction of long neuronal pathways is performed in small successive steps, either deterministic or probabilistic by following the local, voxelwise defined distribution of fiber directions. A major problem of such methods is difficult to resolve regions of crossing fibers by a chain of local decisions. Another problem is that a minor imperfection in the rule of performing local steps can accumulate and significantly affect the final result. |
Download the Algorithm .
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Transcallosal fibers color-coded by their saggital position in corpus callosum.To overcome this problems, we have pioneered a novel, global approach to fiber tracking, in which the number and shape of fibers found in the whole brain are adjusted to the best agreement with measured diffusion-weighted signal (HARDI), taking into account the preliminary knowledge about their geometry. This approach, inspired by the path integral formulation of a free energy in statistical physics, results in a high quality fiber reconstruction within clinically acceptable time frame. The method has been quantitatively validated in a phantom, winning the 1st place at the Fiber Cup, a competition between 10 tracking algorithms, in September 2009. Our global tracking algorithm, together with other quantitative tools, are implemented in our free DTI and Fibertools Software .
Our Method [7] won the FiberCup 2009 ( DMFC in conjuction with MICCAI'09)
Scores and summary , presentation of the winners and summarizing paper
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PhD projects of: Dr. Björn W. Kreher (former group member)
MDT/SDT Method [1]
Detection and resolving of neuronal fiber crossings by using a more complex model than the diffusion tensor resolving more fiber directions and take into account partial volume effects.
Combining Probability Maps [2]
Mapping the probability of connectivity is a powerful tool to determine the fiber structure of white matter in the brain. These probability maps are related to the degree of connectivity of the seed area. Nevertheless, in many applications it is necessary to isolate a fiber bundle connecting two areas. Multiplying two probability maps with different seed areas, results a new map. However, this maps show not exactly the connectivity between the two ROIs, but also fibers starting from these ROIs and join proceeding to another brain region (false-positive). In this paper we introduce a method, suppressing these false-positive detected areas.
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Publications
[1] B.W. Kreher, J. F. Schneider, I. Mader, E. Martin, J. Hennig, K.A. Il'yasov: Multitensor Approach for Analysis and Tracking of Complex Fiber Configurations. Magnetic Resonance in Medicine 54(5), 1216-1225, 2005
[2] B.W. Kreher, S. Schnell, I. Mader, K.A. Il’yasov, J. Hennig, V.G. Kiselev, D. Saur: Connecting and Merging Fibres: Pathway Extraction by Combining Probability Maps. NeuroImage Volume 43, Issue 1, 15 October 2008, Pages 81-89
[3] B.W. Kreher, I. Mader, V.G. Kiselev: Gibbs Tracking: A Novel Approach for the Reconstruction of Neuronal Pathways. Magnetic Resonance in Medicine 60(4), 953-963, 2008
[4] Marco Reisert, Irina Mader, Valerij Kiselev: Tracking a Physical Phantom by Global Fibre Reconstruction. MICCAI 2009, Fiber Cup 2009, Award Winning Program
[5] Marco Reisert, Irina Mader, Valerij Kiselev: Global Reconstruction of Neuronal Fibers. MICCAI 2009, Workshop on Diffusion Modelling and the Fiber Cup, London 2009
[6] Poupon, Rieul, Kezele, Perrin, Poupon, and Mangin: New diffusion phantoms dedicated to the study and validation of high-angular-resolution diffusion imaging (HARDI) models., Magn Reson Med., vol.60, nr.6, 2008, pp 1276-83
[7] Marco Reisert, Irina Mader, Constantin Anastasopoulos, Matthias Weigel, Susanne Schnell, Valerij Kiselev: Global fiber reconstruction becomes practical. NeuroImage 54(2):955-62
[8] Pierre Fillard, Maxime Descoteaux, Alvina Goh, Sylvain Gouttard, Ben Jeurissen, James Malcolm, Alonso Ramirez-Manzanares, Marco Reisert, Ken Sakaie, Fatima Tensaouti, Ting Yo; Jean-François Mangin, Cyril Poupon: Quantitative Analysis of 10 Tractography Algorithms on a Realistic Diffusion MR Phantom NeuroImage, vol. 56(2011): 220-234
