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ANTs Combined Atropos with N4 Bias Correction

Library: ANTs | Docker Image: antsx/ants

Function

Iteratively combines N4 bias field correction with Atropos segmentation for improved results on biased images.

Modality: Brain-extracted 3D NIfTI volume plus brain mask.

Typical Use: Iterative N4 + segmentation for better results on images with bias field.

Key Parameters

-d (dimension), -a (anatomical image), -x (mask), -c (number of classes), -o (output prefix), -n (number of iterations)

Key Points

Iterative approach: N4 correction improves segmentation, which improves next N4 iteration. Superior to running separately.

Inputs

Name Type Required Label Flag
dimensionality int Yes Image dimensionality (2 or 3) -d
input_image File Yes Input anatomical image (typically T1) -a
mask_image File Yes Binary mask defining region of interest -x
output_prefix string Yes Output prefix -o
num_classes int Yes Number of tissue classes -c
n4_atropos_iterations int No Number of N4-Atropos iterations -m
atropos_iterations int No Number of Atropos iterations per N4 iteration -n
prior_images string No Prior probability images pattern (e.g., prior%d.nii.gz) -p
prior_weight double No Atropos prior probability weight -w
n4_shrink_factor int No N4 shrink factor -f
n4_convergence string No N4 convergence parameters -e
n4_bspline string No N4 B-spline parameters -q
atropos_icm string No Atropos ICM parameters -i
use_euclidean_distance boolean No Use Euclidean distance in distance prior -j
posterior_for_n4 int[] No Posterior labels for N4 weight mask -y
image_suffix string No Output image file suffix (e.g., nii.gz) -s
keep_temporary boolean No Keep temporary files -k
use_random_seeding boolean No Use random seeding -u

Accepted Input Extensions

  • input_image: .nii, .nii.gz
  • mask_image: .nii, .nii.gz

Outputs

Name Type Glob Pattern
segmentation File $(inputs.output_prefix)Segmentation.nii.gz
posteriors File[] $(inputs.output_prefix)SegmentationPosteriors*.nii.gz
bias_corrected File $(inputs.output_prefix)Segmentation0N4.nii.gz
log File antsAtroposN4.log

Output Extensions

  • segmentation: .nii.gz
  • posteriors: .nii.gz
  • bias_corrected: .nii.gz

Docker Tags

Available versions: latest, master, v2.6.5, 2.6.5, v2.6.4, 2.6.4, v2.6.3, 2.6.3, v2.6.2, 2.6.2 and 5 more

Categories

  • Structural MRI > ANTs > Segmentation
  • Pipelines > ANTs > Structural

Documentation

Official Documentation