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sub-10013.html11 QSIPrep
Before being analyzed, structural and diffusion neuroimaging data undergo a core set of preprocessing steps. These steps include head motion correction, distortion correction, denoising, Gibbs unringing, coregistration (between structural and functional), and several others. The A2CPS project does this preprocessing with QSIPrep. The QSIPrep derivatives are useful when assessing the quality of preprocessing, or implementing a custom reconstruction or tracking algorithm.
11.1 Starting Project
11.1.1 Locate Data
On TACC, the neuroimaging data are stored underneath the releases. For example, data release v2.#.# is underneath
pre-surgery/mrisThe QSIPrep derivatives are underneath derivatives/qsiprep-V1. Let’s take a look.
11.1.2 Extract Data
For a detailed description of the files produced by QSIPrep, please review their documentation.
11.2 Considerations While Working on the Project
11.2.1 Variability Across Scanners
Many MRI biomarkers exhibit variability across the scanners, which may confound some analyses. For an up-to-date assessment of the issue and overview of current thinking, please see Confluence.
11.2.2 Data Quality
As with any MRI derivative, all pipeline derivatives have been included. This means that products were included regardless of their quality, and so some products may have been generated from images that are known to have poor quality—rated “red”, or incomparable. For details on the ratings and how to exclude them, see Appendix A. Additionally, extensive QC has not yet been performed on the derivatives themselves, and so there may be cases where pipelines produced atypical outputs. For an overview of planned checks, see Confluence.
11.2.3 Data Generation
These outputs were generated by the qsiprep_app.
Preprocessing was performed using QSIPrep 0.21.5.dev0+g36b93fe.d20240504, which is based on Nipype 1.8.6 (K. Gorgolewski et al. (2011); K. J. Gorgolewski et al. (2018); RRID:SCR_002502).
11.2.3.1 Anatomical data preprocessing
The T1-weighted (T1w) image was corrected for intensity non-uniformity (INU) using N4BiasFieldCorrection (Tustison et al., 2010, ANTs 2.4.3), and used as an anatomical reference throughout the workflow. The anatomical reference image was reoriented into AC-PC alignment via a 6-DOF transform extracted from a full Affine registration to the MNI152NLin2009cAsym template. A full nonlinear registration to the template from AC-PC space was estimated via symmetric nonlinear registration (SyN) using antsRegistration. Brain extraction was performed on the T1w image using SynthStrip (Hoopes et al., 2022) and automated segmentation was performed using SynthSeg Billot, Magdamo, et al. (2023) from FreeSurfer version 7.3.1.
11.2.3.2 Diffusion data preprocessing
Any images with a b-value less than 100 s/mm^2 were treated as a b=0 image. Denoising using patch2self (Fadnavis et al., 2020) was applied with settings based on developer recommendations. After patch2self, Gibbs unringing was performed using MRtrix3’s mrdegibbs (Kellner et al., 2016). Following unringing, the mean intensity of the DWI series was adjusted so all the mean intensity of the b=0 images matched across eachseparate DWI scanning sequence. B1 field inhomogeneity was corrected using dwibiascorrect from MRtrix3 with the N4 algorithm (Tustison et al., 2010) after corrected images were resampled.
FSL (version None)’s eddy was used for head motion correction and Eddy current correction (J. L. R. Andersson & Sotiropoulos, 2016). Eddy was configured with a \(q\)-space smoothing factor of 10, a total of 5 iterations, and 1000 voxels used to estimate hyperparameters. A linear first level model and a linear second level model were used to characterize Eddy current-related spatial distortion. \(q\)-space coordinates were forcefully assigned to shells. Field offset was attempted to be separated from subject movement. Shells were aligned post-eddy. Eddy’s outlier replacement was run (J. L. R. Andersson et al., 2016). Data were grouped by slice, only including values from slices determined to contain at least 250 intracerebral voxels. Groups deviating by more than 4 standard deviations from the prediction had their data replaced with imputed values.
Data was collected with reversed phase-encode blips, resulting in pairs of images with distortions going in opposite directions. FSL’s TOPUP (J. L. Andersson et al., 2003) was used to estimate a susceptibility-induced off-resonance field based on b=0 reference images with reversed phase encoding directions. The TOPUP-estimated fieldmap was incorporated into the Eddy current and head motion correction interpolation. Final interpolation was performed using the jac method.
Several confounding time-series were calculated based on the preprocessed DWI: framewise displacement (FD) using the implementation in Nipype (following the definitions by Power et al., 2014). The head-motion estimates calculated in the correction step were also placed within the corresponding confounds file. Slicewise cross correlation was also calculated. The DWI time-series were resampled to ACPC, generating a preprocessed DWI run in ACPC space with 1.7mm isotropic voxels.
Many internal operations of QSIPrep use Nilearn 0.10.1 (Abraham et al., 2014, RRID:SCR_001362) and Dipy (Garyfallidis et al., 2014). For more details of the pipeline, see the section corresponding to workflows in QSIPrep’s documentation.
11.2.4 Citations
If you use these products in your analyses, please cite the relevant papers written by members TReNDS.
In publications or presentations including data from A2CPS, please include the following statement as attribution:
Data were provided [in part] by the A2CPS Consortium funded by the National Institutes of Health (NIH) Common Fund, which is managed by the Office of the Director (OD)/ Office of Strategic Coordination (OSC). Consortium components and their associated funding sources include Clinical Coordinating Center (U24NS112873), Data Integration and Resource Center (U54DA049110), Omics Data Generation Centers (U54DA049116, U54DA049115, U54DA049113), Multi-site Clinical Center 1 (MCC1) (UM1NS112874), and Multi-site Clinical Center 2 (MCC2) (UM1NS118922).
When using neuroimaging derivatives, please also cite Sadil et al. (2024).