---
configs:
- config_name: sample_manifest
  data_files:
  - split: sample
    path: sample/sample_manifest.csv
  default: true
---

# OpenBrain v1.0

OpenBrain v1.0 is a public-ready release of brain-extracted T1-weighted MRI
images, SynthStrip-derived brain masks, and automated whole-brain segmentation
labels.

## Release Contents

- Cases: 35,838
- Source OpenNeuro datasets: 607
- License: CC0
- Artifacts per case:
  - `image.nii.gz`: revised brain-extracted T1w image
  - `brain_mask.nii.gz`: SynthStrip-derived brain mask
  - `whole_brain_segmentation.nii.gz`: automated whole-brain segmentation label

All released cases are derived from raw T1w images that were exactly matched to
verified public OpenNeuro snapshots with CC0/public-domain-compatible license
metadata. The segmentation labels are algorithmic labels, not manual ground
truth.

## Layout

```text
cases/<case_id>/image.nii.gz
cases/<case_id>/brain_mask.nii.gz
cases/<case_id>/whole_brain_segmentation.nii.gz
metadata/openbrain_v1_0_metadata.csv
metadata/sha256_manifest.csv
sample/cases/<case_id>/...
sample/sample_manifest.csv
sample/README.md
```

## QC Manifest Fields

The QC manifest uses `Q1`--`Q7` for the raw OpenBrain QC-7 values and
`r1`--`r7` for the corresponding source-local percentile risk fields. Larger
`r_k` values indicate higher risk relative to cases from the same OpenNeuro
source dataset; they are not calibrated probabilities of segmentation
correctness. `R` is the aggregate QC-7 risk score, and `tier` is the confidence
tier derived from the fixed release operating points.

The public sample manifest under `sample/sample_manifest.csv` follows the same
QC field convention for the 64-case reviewer sample subset.

## Reviewer Sample

The `sample/` directory is a 64-case reviewer preview subset. Every sample case
is drawn from the HighConf tier and includes the same three case artifacts as
the full release: `image.nii.gz`, `brain_mask.nii.gz`, and
`whole_brain_segmentation.nii.gz`. The sample is source-diverse (one case per
source dataset) and selected by low combined risk `R`, with Q1/Q3/Q4
visual-cleanliness tie-breaks.

Use it for visual inspection, download testing, and pipeline smoke tests. The
labels remain algorithmic pseudo-labels, not manual ground truth.

## Exclusions

This release excludes cases with non-CC0 licenses, missing OpenNeuro provenance,
manual-review license status, ambiguous raw BIDS matches, or missing raw T1w
matches. OpenMind-derived quality scores and masks are not included.