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MRI PET BrainHead

OpenMind

The OpenMind Dataset: 3D head-and-neck MRI pooled from 800 OpenNeuro datasets for self-supervised learning

113,921 3D head and brain volumes (all MRI except 653 PET) from 800 OpenNeuro datasets and about 34,000 subjects, with diffusion-derived maps, defacing and anatomy masks and harmonized metadata, for self-supervised pre-training. CC BY 4.0 on Hugging Face.

Overview

OpenMind is a pre-training collection of 3D head and brain images assembled by the Division of Medical Image Computing at the German Cancer Research Center (DKFZ). The authors took every 3D MRI and every 4D diffusion scan they could find in 800 public OpenNeuro datasets, converted the diffusion scans into 3D maps, and released the result on Hugging Face together with a benchmark of 3D self-supervised learning methods, the code and the pre-trained models. It holds no task labels and is meant for pre-training, not for supervised training or evaluation.

Composition

The paper reports 113,921 volumes. Of these, 653 are PET, and 40,221 are fractional anisotropy, mean diffusivity and T2-weighted volumes computed from 13,407 diffusion scans. The volumes are grouped into 24 image types; T1w (42,732) and T2w (22,999) dominate, followed by FA and MD maps, FLAIR and MP2RAGE. Smaller groups include 784 SWI, 687 minimum intensity projections, 409 T2*-weighted and 76 T2* map volumes. The subject count differs inside the paper (34,139 in the text, 34,191 in the tables). Twelve source datasets contribute half of all volumes.

Acquisition

The data come from many independent studies, so protocols, scanners and resolutions vary. The harmonized metadata name Siemens, Philips and GE scanners and field strengths from 1.5 to 9.4 T, mostly 3 T, but manufacturer and field strength are missing for about a quarter of the images. Age, sex, handedness, BMI, race and health status are filled in only where the source dataset reported them.

Annotations

Each image has a defacing mask that marks anonymized regions and an anatomy mask that marks where tissue is present, created with an automated model where the source did not provide them. Two raters scored two example images per image type and source dataset for noise, blur and artifacts; the resulting image quality score from 1 (best) to 5 applies to all images of that type in that dataset.

Known limitations

  • The quality score is per source dataset and image type, not per image.
  • Many images are skull-stripped, defaced or face-blurred, which can affect reconstruction-based pre-training.
  • Each source dataset keeps its own OpenNeuro license, and the same person may appear in more than one source dataset.
  • Image types come from the source BIDS labels, which are named inconsistently; the authors say the grouping into 24 types is approximate.

Cohort

Aggregate numbers from the sources below. Bars are relative to the 34,139 subjects.

Sex

  • Female 12,543 55%
  • Male 10,300 45%

Covers 22,843 of 34,139 subjects.

Age

· range 2 to 100
0
5,000
10,000
11,061
0-910-1920-2930-3940-4950-5960-6970-7980-8990+

Modality

scans

  • MRI 113,268 99%
  • PET 653 <1%

Contrast / sequence

scans, values can overlap

  • T1-weighted 42,732 38%
  • T2-weighted 22,999 20%
  • FLAIR 5,583 5%
  • MP2RAGE 2,859 3%
  • ADC map 1,757 2%
  • Susceptibility-weighted 784 <1%
  • T1 map 557 <1%
  • MR angiography 488 <1%
  • Proton density weighted 473 <1%
  • T2*-weighted 409 <1%
  • T2 map 106 <1%
  • Diffusion-weighted 55 <1%

Condition

subjects, values can overlap

  • Healthy control 5,262 15%

Scanner vendor

scans

  • Siemens Healthineers 64,415 57%
  • Philips 14,580 13%
  • GE HealthCare 8,114 7%

Field strength

scans

  • 3 T 75,107 66%
  • 1.5 T 5,948 5%
  • 7 T 1,329 1%
  • 9.4 T 86 <1%

License and access

Our reading of the license, not legal advice. Before you use the data, read the original license and confirm that your use is allowed. We take no responsibility for how you use a dataset. Full disclaimer

Access
Open download

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Creative Commons Attribution 4.0 International

Use, share and adapt the data for any purpose, including commercial use, as long as you credit the creators.

The Hugging Face dataset card declares cc-by-4.0, and the paper (Table 1) lists the dataset as CC-BY-4.0. The images come from OpenNeuro datasets that each carry their own license.

Original license text Version read: 4.0 Checked 2026-10-07

What you can do

  • Yes
  • Yes
  • Yes
  • Yes

What you can share

  • Yes
  • Yes
  • Yes

What you must do

  • Yes
  • Share alike No
  • No
  • No
  • Manuscript review No
  • Release code No
  • Return results No
  • Delete after use No

Limits

  • No
  • Location limits No

Citation

Wald T, Ulrich C, Suprijadi J, Ziegler S, Nohel M, Peretzke R, Köhler G, Maier-Hein KH. An OpenMind for 3D medical vision self-supervised learning. arXiv:2412.17041 (2024).

@article{wald2024openmind,
  title={An OpenMind for 3D medical vision self-supervised learning},
  author={Wald, Tassilo and Ulrich, Constantin and Suprijadi, Jonathan and Ziegler, Sebastian and Nohel, Michal and Peretzke, Robin and K{\"o}hler, Gregor and Maier-Hein, Klaus H.},
  journal={arXiv preprint arXiv:2412.17041},
  year={2024}
}

All numbers

Every number on this page, as stored in stats.csv, with its source.

MeasureBreakdownValueSource
Subjectstotal
Table 1 and Appendix B.3 give 34,191; the metadata file has 34,139 unique dataset and subject pairs. The same person can appear in more than one OpenNeuro dataset.
34,139wald2024
Section 2.1
Scanstotal
3D volumes, including 653 PET and 40,221 volumes derived from 13,407 diffusion scans; the metadata file has 113,921 rows
113,921wald2024
Appendix B.3
Scansmodality=PT
footnote 1
653wald2024
Section 2.1
Scansmodality=MR
all rows except PET
113,268openmind-metadata
modality
Scanscontrast=T1w 42,732wald2024
Table 9
Scanscontrast=T2w
includes 13,407 T2-weighted volumes derived from diffusion scans (metadata column derived_from)
22,999wald2024
Table 9
Scanscontrast=FLAIR 5,583wald2024
Table 9
Scanscontrast=MP2RAGE
UNIT1 (927) and UNIT1_denoised (724) are listed separately
2,859wald2024
Table 9
Scanscontrast=ADC 1,757wald2024
Table 9
Scanscontrast=swi
minimum intensity projections (minIP, 687) are listed separately
784wald2024
Table 9
Scanscontrast=T1map 557wald2024
Table 9
Scanscontrast=angio 488wald2024
Table 9
Scanscontrast=PDw 473wald2024
Table 9
Scanscontrast=T2starw
T2* maps (T2starmap, 76) are listed separately
409wald2024
Table 9
Scanscontrast=T2map 106wald2024
Table 9
Scanscontrast=dwi
remaining DWI volumes; the 13,407 diffusion scans were converted into FA, MD and T2w volumes
55wald2024
Table 9
Scansvendor=siemens 64,415openmind-metadata
manufacturer
Scansvendor=philips 14,580openmind-metadata
manufacturer
Scansvendor=ge
26,811 rows have no manufacturer
8,114openmind-metadata
manufacturer
Scansfield_strength=1.5 5,948openmind-metadata
magnetic_field_strength
Scansfield_strength=3
75,069 rows with 3.0 plus 38 with 2.89362 (the nominal value some 3 T Siemens scanners report)
75,107openmind-metadata
magnetic_field_strength
Scansfield_strength=7
335 rows with 7.0 plus 994 with 6.98
1,329openmind-metadata
magnetic_field_strength
Scansfield_strength=9.4
30,104 rows have no field strength; 1,342 rows with 3.95064 and 5 with 15000.0 are left out
86openmind-metadata
magnetic_field_strength
Subjectssex=female
subjects whose images list female
12,543openmind-metadata
unique_id, sex
Subjectssex=male
subjects whose images list male; 11,296 subjects have no sex
10,300openmind-metadata
unique_id, sex
Subjectscondition=healthy
3,285 subjects are listed as ill, the rest have no health status
5,262openmind-metadata
unique_id, health_status
Subjectsage=0-9
age as given in the harmonized metadata; 20,951 subjects have an age
591openmind-metadata
unique_id, age
Subjectsage=10-19 3,060openmind-metadata
unique_id, age
Subjectsage=20-29 11,061openmind-metadata
unique_id, age
Subjectsage=30-39 2,437openmind-metadata
unique_id, age
Subjectsage=40-49 971openmind-metadata
unique_id, age
Subjectsage=50-59 910openmind-metadata
unique_id, age
Subjectsage=60-69 983openmind-metadata
unique_id, age
Subjectsage=70-79 676openmind-metadata
unique_id, age
Subjectsage=80-89 257openmind-metadata
unique_id, age
Subjectsage=90+ 5openmind-metadata
unique_id, age
Median agetotal
20,951 subjects with an age
24openmind-metadata
unique_id, age
Minimum agetotal 2openmind-metadata
unique_id, age
Maximum agetotal 100openmind-metadata
unique_id, age

Sources

The keys used in the table above.