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QSIPrep

QSIPrep configures pipelines for processing diffusion-weighted MRI (dMRI) data. The main features of this software are:

The preprocessing pipelines are built based on the available BIDS inputs, ensuring that fieldmaps are handled correctly. The preprocessing workflow performs head motion correction, susceptibility distortion correction, MP-PCA denoising, coregistration to T1w images, spatial normalization using ANTs and tissue segmentation.

Usage

QSIprep should be used through a container. A command like:

qsiprep <input_dir>/ <output_dir>/ participant [OPTIONS]

with [OPTIONS] specific to your dataset is easily invoked with either Docker or Apptainer to use this tool.

You are also able to use Nipoppy!

Output Structure

QSIPrep generates three broad classes of outcomes:

The file structure should resemble something like this:

sub-<label>/
  anat/
	sub-<label>_from-anat_to-ACPC_mode-image_xfm.mat
	sub-<label>_from-ACPC_to-anat_mode-image_xfm.mat
	sub-<label>_from-ACPC_to-<output-space>_mode-image_xfm.h5
	sub-<label>_from-<output-space>_to-ACPC_mode-image_xfm.h5
ses-<label>/
	anat/
		# Brain mask derived from SynthStrip
		<source_entities>_space-ACPC_desc-brain_mask.nii.gz

		# Tissue-probability maps
		<source_entities>_space-ACPC_label-CSF_probseg.nii.gz
		<source_entities>_space-ACPC_label-GM_probseg.nii.gz
		<source_entities>_space-ACPC_label-WM_probseg.nii.gz

		# Tissue class map derived SynthSeg
		<source_entities>_space-ACPC_dseg.nii.gz

		# Bias field corrected T1w file, using ANTS' N4BiasFieldCorrection
		<source_entities>_space-ACPC_desc-preproc_T1w.nii.gz

		# The same files as above, but in the selected output space.
		<source_entities>_space-MNI152NLin2009cAsym_desc-brain_mask.nii.gz
		<source_entities>_space-MNI152NLin2009cAsym_label-CSF_probseg.nii.gz
		<source_entities>_space-MNI152NLin2009cAsym_label-GM_probseg.nii.gz
		<source_entities>_space-MNI152NLin2009cAsym_label-WM_probseg.nii.gz
		<source_entities>_space-MNI152NLin2009cAsym_dseg.nii.gz
		<source_entities>_space-MNI152NLin2009cAsym_desc-preproc_T1w.nii.gz

		sub-<label>_ses-<label>_from-orig_to-anat_mode-image_xfm.txt
		sub-<label>_ses-<label>_from-anat_to-orig_mode-image_xfm.txt

	dwi/

		# A tab-separated value file with one column per calculated confound
		# and one row per timepoint/volume
		<source_entities>_desc-confounds_timeseries.tsv

		<source_entities>_space-ACPC_dwiref.nii.gz

		# The generous brain mask that should be reduced probably
		<source_entities>_space-ACPC_desc-brain_mask.nii.gz
		<source_entities>_space-ACPC_desc-preproc_dwi.nii.gz

		# FSL-style bval and bvec files.
		# These will be incorrectly interpreted by MRTrix,
		# but will work with DSI Studio and Dipy.
		<source_entities>_space-ACPC_desc-preproc_dwi.bval
		<source_entities>_space-ACPC_desc-preproc_dwi.bvec

		# Use the ``.b`` file for MRTrix.
		# The gradient table to import data into MRTrix.
		# This can be used with the preprocessed DWI file and
		# converted directly to a ``.mif`` file using the
		# ``mrconvert -grad _dwi.b`` command.
		<source_entities>_space-ACPC_desc-preproc_dwi.b

		# Contrast-to-noise model defined as the variance of the
		# signal model divided by the variance of the error of the signal model.
		<source_entities>_space-ACPC_stat-cnr_desc-<label>_dwimap.json
		<source_entities>_space-ACPC_stat-cnr_desc-<label>_dwimap.nii.gz

Naturally, different versions and analysis options can change what files appear.

References

Cieslak, M., Cook, P. A., He, X., Yeh, F. C., Dhollander, T., Adebimpe, A., ... & Satterthwaite, T. D. (2021). QSIPrep: an integrative platform for preprocessing and reconstructing diffusion MRI data. Nature methods, 18(7), 775-778.