The second-level analysis utilized FLAME (
FMRIB's Local Analysis of Mixed Effects; Woolrich et al., 2004), a process that allows for estimation of mixed effects variance.
Each FA image was normalized spatially to the target image with
FMRIB's Nonlinear Image Registration Tool (FNIRT, part of FSL).
Abbreviations BMI: Body mass index QST: Quantitative Sensory Testing IENFD: Intraepidermal nerve fiber density MRI: Magnetic resonance imaging EV: Epineurial volume FV: Fascicles volume NV: Nerve volume FNR: Fascicles to nerve volumes ratio CSA: Cross-sectional area SPGR: Spoiled gradient echo IDEAL: Iterative decomposition of water and fat with echo asymmetry and least-squares estimation FAST:
FMRIB Automated Segmentation Tool.
The
FMRIB's linear image registration tool (FLIRT) [105] and
FMRIB's nonlinear image registration tool (FNIRT) are excellent software that can accomplish this goal.
Analysis for DTI was performed by the
FMRIB Diffusion Toolbox from the FSL processing software package (http://www.fmrib.ox.ac.uk/fsl).
ASL data analysis and perfusion quantification were performed using a custom version of the BASIL toolbox from the
FMRIB Software Library (http://www.fmrib.ox.ac.uk/fsl/BASIL).
First, we analyzed the fMRI data acquired during the face processing task to compare between the emotional face condition and the control condition using the fMRI Expert Analysis Tool (FEAT) Version 6.0, which is part of
FMRIB's Software Library (FSL, http://www.fmrib.ox.ac.uk/fsl) for extracting the ROIs in the gray matter associated with face processing.
The CBF maps from each day and session were exported from the MRI scanner and processed using the
FMRIB Software Library (FSL) [34, 35] on a 74-core Rocks Cluster Distribution (http://www.rocksclusters.org) high-performance computing system capable of running 120 threads in parallel (see Figure 1, e.g., CBF maps).
Data were preprocessed using
FMRIB's Software Library (v.
Preprocessing was performed with Statistical Parametric Mapping software (SPM8, http://www.fil.ion.ucl.ac.uk/spm/software/spm8/), the Analysis of Functional NeuroImage (AFNI, http://afni.nimh.nih.gov/afni) package, and the
FMRIB Software Library (FSL, http://fsl.fmrib.ox.ac.uk/fsl).
Then
FMRIB Software Library (FSL) by the Oxford Centre for Functional MRI of the Brain, and in particular its diffusion toolkit FDT, was used for the complete image processing pipeline; see Figure 1 for the overall flowchart:
Functional neuroimaging data analysis was carried out using FEAT (FMRI Expert Analysis Tool) Version 6, part of FSL (
FMRIB's Software Library, http://www.fmrib.ox.ac.uk/fsl).