---
license: cc-by-4.0
task_categories:
- image-segmentation
tags:
- medical
- mri
- lumbar-spine
- segmentation
- vertebrae
- intervertebral-disc
- spinal-canal
size_categories:
- n<1K
configs:
- config_name: default
  data_files:
  - split: training
    path: data/training-*
  - split: validation
    path: data/validation-*
dataset_info:
  features:
  - name: patient_id
    dtype: string
  - name: sequence
    dtype: string
  - name: series
    dtype: string
  - name: subset
    dtype: string
  - name: num_vertebrae
    dtype: int32
  - name: num_discs
    dtype: int32
  - name: sex
    dtype: string
  - name: manufacturer
    dtype: string
  - name: model
    dtype: string
  - name: magnetic_field_strength
    dtype: float32
  - name: num_slices
    dtype: int32
  - name: shape_zyx
    list: int32
  - name: num_label_classes
    dtype: int32
  - name: image_middle_slice
    dtype: image
  - name: mask_middle_slice
    dtype: image
  - name: overlay_middle_slice
    dtype: image
  splits:
  - name: training
    num_bytes: 35627666
    num_examples: 360
  - name: validation
    num_bytes: 10866295
    num_examples: 87
  download_size: 46479041
  dataset_size: 46493961
---

# SPIDER — Lumbar Spine Segmentation in MR Images

Public release of the SPIDER dataset: 218 patients, 447 sagittal lumbar-spine MRI series with reference segmentations of vertebrae, intervertebral discs (IVDs), and spinal canal. Source: van der Graaf et al., *Scientific Data* 11:264 (2024).

## Contents

| Path | Description |
|------|-------------|
| `images/images/` | 447 `.mha` MRI volumes — naming `{patient_id}_{t1|t2|t2_SPACE}.mha` (196 T1 + 210 T2 + 41 T2-SPACE) |
| `masks/masks/`   | 447 `.mha` reference segmentations, one per image |
| `overview.csv`   | Per-series metadata: subset (training/validation), sex, vendor, sequence parameters, etc. |
| `radiological_gradings.csv` | Per-IVD radiological gradings (Modic, Pfirrmann, herniation, etc.) |

## Splits

Split assignment is in `overview.csv` column `subset`:

- **training** — 360 series
- **validation** — 87 series

(The Grand Challenge hidden test set of 39 patients is **not** included; it is only accessible via https://spider.grand-challenge.org/.)

## Label Scheme (masks)

- Vertebrae: sequential integer labels (numbered top-down)
- IVDs: labeled by the vertebra immediately above (lowest IVD = 201, next up = 202, ...)
- Spinal canal: 100
- Background: 0

## Recommended Ground Truth

Use `masks/masks/`. The 41 T2-SPACE series are the most authoritative tier (fully manual annotation on near-isotropic, higher-resolution voxels). T1/T2 masks were produced by iterative semi-automatic refinement under MSK-radiologist supervision.

## Source

- **Paper**: van der Graaf, J. W., et al. (2024). Lumbar spine segmentation in MR images: a dataset and a public benchmark. *Sci Data* 11, 264. doi:10.1038/s41597-024-03090-w
- **Original Zenodo**: https://zenodo.org/records/10159290
- **Grand Challenge**: https://spider.grand-challenge.org/
- **License**: CC-BY 4.0

This HuggingFace mirror reproduces the Zenodo v4 release (Nov 2023, modified Mar 2024) without modification.