Symmetric Positive 4th-order Diffusion Tensor EstimatorYou can use this applet to estimate a 4th-order diffusion tensor from given DW-MRI signal values associated with a list of magnetic gradient directions. This method computes the coefficients of a symmetric positive-definite 4th-order diffusion tensor using the algorithm presented by A. Barmpoutis et al. "Regularized Positive Definite Fourth Order Tensor Field Estimation from DW-MRI", NeuroImage, 2009. An implementation of this algorithm is also available to download here. |
InstructionsTechnical details: This method computes the 15 unique coefficients of a symmetric positive-definite 4th-order diffusion tensor using the algorithm presented by A. Barmpoutis et al. "Regularized Positive Definite Fourth Order Tensor Field Estimation from DW-MRI", NeuroImage, 2009. The output is the list of the estimated coefficients in the following order: D400, D040 D004, D220, D022, D202, D211, D121, D112, D310, D301, D130, D031, D103, D013. The input is a list of unit vectors (magnetic gradient directions) and the corresponding DW-MRI S/S0 signal attenuations. In this demonstration the input b-value is assumed to be 1500s/mm2. First define the input values and then hit the RUN button. The 3D plot displays the estimated diffusivity function and the corresponsing input samples (red dots).Generate synthetic data: You can test this method on synthetic DW-MRI data. DW-MRI datasets from fiber crossings can be generated by using the synthetic data generator. System requirements: Please use Internet Explorer (Microsoft) with the latest JAVA platform installed. Disclaimer: You can use this free software for non commercial research purposes and demonstration only without licensing fees and is provided without guarantee or warrantee expressed or implied. This program is NOT in the public domain. Patent pending. This software can be downloaded from here For questions please feel free to contact me: Angelos Barmpoutis, abarmpou [at] cise [dot] ufl [dot] edu |