BIDS Pipelines (--bids-prep / --bids-post)

BIDS Pipelines¶

CLI flags: --bids-prep [rest|dwi], --bids-post [rest|dwi]

What is a BIDS pipeline?¶

A BIDS pipeline is any two-step, containerized workflow that operates directly on BIDS-formatted data. The two steps map cleanly onto a preprocessing → postprocessing structure:

• --bids-prep runs the primary preprocessing container (e.g. fMRIPrep, QSIPrep). This step is computationally heavy and produces minimally preprocessed outputs.

• --bids-post runs a downstream analysis container on those outputs (e.g. XCP-D for functional connectivity, QSIRecon for tractography). It automatically waits for --bids-prep to finish.

The two built-in examples follow this pattern:

Both steps run as SLURM array jobs (one job per subject) and are independent of --intermed — they depend only on recon. Multiple modalities requested together run in parallel:

[recon]
     |
     +-- [rest_preprocess]  →  [rest_post]
     +-- [dwi_preprocess]   →  [dwi_post]

You can run prep and post together or separately, and combine multiple modalities in one command:

neuropipe run ... --bids-prep rest,dwi --bids-post rest,dwi

Any containerized two-step pipeline that follows this recon → prep → post pattern can be added as a new BIDS section in config.yaml — the tool inside the container is irrelevant to the framework.

Resting-State fMRI (rest)¶

rest_preprocess¶

What it does: Full anatomical and functional preprocessing with fMRIPrep — motion correction, distortion correction, surface/volume normalization.

Tool: fMRIPrep (Singularity)
SLURM profile: heavy_long (64 GB, 24 h) — array job
Script: fmriprep_rs.sh
Depends on: recon
Input: {output}/BIDS/
Output: {output}/BIDS_derivatives/fmriprep/

Config entry:

tasks:
  rest_preprocess:
    remove_TRs: 6
    template: "MNI152NLin2009cAsym"
    container: "fmriprep_25.1.3.sif"
    license: "license.txt"

rest_post¶

What it does: Post-processing of fMRIPrep outputs with XCP-D — nuisance regression, bandpass filtering, functional connectivity matrix computation.

Tool: XCP-D (Singularity)
SLURM profile: standard_short (32 GB, 8 h) — array job
Script: xcpd_rs.sh
Depends on: rest_preprocess
Input: {output}/BIDS_derivatives/fmriprep/
Output: {output}/BIDS_derivatives/xcpd/

Config entry:

tasks:
  rest_post:
    remove_TRs: 6
    template: "MNI152NLin2009cAsym"
    container: "xcp_d-0.11.0rc1.sif"
    rest_mode: "abcd"
    motion_filter_type: "notch"
    band_stop_min: "15"
    band_stop_max: "25"
    nuisance_regressors: "36P"
    license: "license.txt"

Usage¶

# Full resting-state pipeline
neuropipe run \
  --subjects 001,002 \
  --input /data/BIDS \
  --output /data/processed \
  --work /data/work \
  --project my_study \
  --session 01 \
  --bids-prep rest \
  --bids-post rest

# XCP-D only (fMRIPrep already complete)
neuropipe run ... --bids-post rest

Diffusion MRI (dwi)¶

dwi_preprocess¶

What it does: DWI preprocessing with QSIPrep — denoising, susceptibility distortion correction, eddy current correction, motion correction, and template registration.

Tool: QSIPrep (Singularity)
SLURM profile: standard (32 GB, 20 h) — array job
Script: qsiprep.sh
Depends on: recon
Input: {output}/BIDS/
Output: {output}/BIDS_derivatives/qsiprep/

Config entry:

dwi_post¶

What it does: Tractography and connectivity matrix computation with QSIRecon.

Tool: QSIRecon (Singularity)
SLURM profile: standard (32 GB, 20 h) — array job
Script: qsirecon.sh
Depends on: dwi_preprocess
Input: {output}/BIDS_derivatives/qsiprep/
Output: {output}/BIDS_derivatives/qsirecon/

Config entry:

Usage¶

# Full DWI pipeline
neuropipe run \
  --subjects 001,002 \
  --input /data/BIDS \
  --output /data/processed \
  --work /data/work \
  --project my_study \
  --session 01 \
  --bids-prep dwi \
  --bids-post dwi

# Preprocessing only
neuropipe run ... --bids-prep dwi

# QSIRecon only (QSIPrep already complete)
neuropipe run ... --bids-post dwi

Adding a new BIDS pipeline¶

Any two-step containerized pipeline that follows the recon → prep → post pattern can be added as a new BIDS section in config.yaml. See How-To: Add a Custom Task.