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FMRIB's Integrated Registration and Segmentation Tool (FIRST)

Library: FSL | Docker Image: brainlife/fsl

Function

Multi-step pipeline for subcortical structure segmentation. Internally chains registration, boundary correction, and shape-model segmentation for 15 subcortical structures.

Modality: T1-weighted 3D NIfTI volume (does not need to be brain-extracted).

Typical Use: Volumetric analysis of subcortical structures (hippocampus, amygdala, caudate, etc.).

Key Parameters

-i (input image), -o (output basename), -b (run BET first), -s (comma-separated structures list)

Key Points

Models 15 subcortical structures. Outputs meshes (.vtk) and volumetric labels. Can run on selected structures only with -s flag.

Inputs

Name Type Required Label Flag
input File Yes Input T1-weighted image -i
output string Yes Output basename -o
brain_extracted boolean No Input is already brain extracted -b
method enum No Boundary correction method -m
structures string No Run only on specified structures (comma-separated list) -s
affine File No Use this affine matrix for registration -a
three_stage boolean No Use 3-stage registration -3
verbose boolean No Verbose output -v
debug boolean No Debug mode (don't delete temporary files) -d

Accepted Input Extensions

  • input: .nii, .nii.gz
  • affine: .mat

Outputs

Name Type Glob Pattern
segmentation_files File[] $(inputs.output)_all_fast_firstseg.nii.gz, $(inputs.output)_all_fast_origsegs.nii.gz, $(inputs.output)-*_first.nii.gz
vtk_meshes File[] $(inputs.output)-*.vtk
bvars File[] $(inputs.output)-*.bvars
log File run_first_all.log

Output Extensions

  • segmentation_files: .nii.gz
  • vtk_meshes: .vtk
  • bvars: .bvars

Enum Options

method: auto, fast, none

Docker Tags

Available versions: latest, 6.0.4-patched2, 6.0.4-patched, 6.0.4, 6.0.4-xenial, 5.0.11, 6.0.0, 6.0.1, 5.0.9

Categories

  • Structural MRI > FSL > Tissue Segmentation
  • Pipelines > FSL > Structural

Documentation

Official Documentation