Geforce gt425

Data from a simulation study and in vivo data of healthy volunteers as well as patients with different brain lesions were used. The processing and visualization was performed on a Linux (Ubuntu 14.04) workstation with an Intel Core i7 processor, 8 GB RAM, and NVIDIA GeForce GT425 graphics card.

For the in vivo datasets we used a mutual information-based retrospective motion correction scheme in order to remove motion that occurred during the scan. For the simulated and in vivo datasets we computed the diffusion tensor for each voxel and additionally reconstructed the FOD with the constrained spherical deconvolution algorithm using a maximum spherical harmonic order l_max⁡ = 8. We determined one or two main directions for each voxel by detecting the FOD's local maxima. To determine the local maxima of the FOD we reconstructed the FOD using 606 reconstruction directions, distributed over a hemisphere. A local maximum of the FOD is valid if (i) it reaches at least 50% of the global maximum, (ii) its direction does not deviate less than an angle of 30° from all previously found peaks, and (iii) all neighboring values on the FOD surface are smaller. The processing and visualization were performed on a Linux (Ubuntu 11.04) workstation with the following specifications: Intel Core i7-3630QM (8MB cache, 2 GHz × 8 cores with hyperthreading), 8 GB RAM (DDR3, 1333 MHz), and NVIDIA GeForce GT425 (with 1 GByte memory) graphics card. All processing steps were performed using the modular software platform OpenPDT developed by our group.