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Open Imaging Index
MRI Brain

IXI

Information eXtraction from Images

Brain MRI of healthy adults with demographics, one of the oldest openly licensed collections and widely used for brain age prediction, contrast synthesis and as a healthy reference. Nearly 600 people from three London hospitals with T1, T2, PD, angiography and diffusion images.

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Overview

IXI is one of the oldest openly licensed brain MRI collections and is still widely used for brain age prediction, image synthesis between contrasts and as a healthy reference population.

Composition

About 600 healthy adults were scanned once. Each session aimed to acquire T1-weighted, T2-weighted and proton-density images, a time-of-flight MR angiogram and a diffusion scan with 15 directions. Not every subject has every image.

Acquisition

Three London hospitals contributed:

Site Scanner
Hammersmith Hospital (HH) Philips 3T
Guy's Hospital (Guys) Philips 1.5T
Institute of Psychiatry (IOP) GE 1.5T

The site is part of every file name, e.g. IXI002-Guys-0828-T1.nii.gz.

Demographics

The spreadsheet lists 593 unique subject ids. 565 of them have an age, and the age and sex counts on this page cover those 565 people. The spreadsheet also records height, weight and self-reported ethnicity.

Known limitations

  • The website does not say whether faces were removed from the images.
  • Acquisition parameters for the IOP scanner are not documented.
  • Some ids appear several times in the spreadsheet with different rows.

Cohort

Aggregate numbers from the sources below. Bars are relative to the 600 subjects.

Sex

  • Female 312 55%
  • Male 253 45%

Covers 565 of 600 subjects.

From IXI.xls demographics spreadsheet (CC BY-SA 3.0), counted per unique subject with an age

Age

mean 48.6 ± 16.5, median 48.7, range 20 to 86.3

0
50
100
119
10-1920-2930-3940-4950-5960-6970-7980+

From IXI.xls demographics spreadsheet (CC BY-SA 3.0), counted per unique subject with an age

Age by sex

Reported cross table. Missing cells were not published (fewer than 10 or not reported).

Female Male
  • 34
    70-79
    15
  • 71
    60-69
    48
  • 61
    50-59
    38
  • 48
    40-49
    41
  • 39
    30-39
    60
  • 55
    20-29
    46

From IXI.xls demographics spreadsheet (CC BY-SA 3.0), counted per unique subject with an age

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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Access page

Creative Commons Attribution-ShareAlike 3.0 Unported

Older version of CC BY-SA. Use, share and adapt for any purpose with credit. Anything you share that is built on the data must use the same license.

Original license text Version read: 3.0 Checked 2026-10-07

What you can do

  • Yes
  • Yes
  • Yes
  • Yes
  • Yes

What you can share

  • Yes
  • Conditional
  • Conditional

What you must do

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

Limits

  • No
  • Location limits No

Citation

IXI Dataset, Biomedical Image Analysis Group, Imperial College London. https://brain-development.org/ixi-dataset/

Sources

Every number on this page comes from one of these documents. Each chart names the table or page it is taken from. The raw numbers are in stats.csv.