MedOtter/isles2017

ISLES 2017 — Ischemic Stroke Lesion Segmentation Challenge (Outcome Prediction)

Multispectral brain MRI from the MICCAI 2017 edition of the Ischemic Stroke Lesion Segmentation (ISLES) challenge. The 2017 task is lesion outcome prediction: estimate the final infarct (segmented on a ~90-day follow-up scan) from acute multispectral MRI.

This repository contains the public training split only (43 cases), every case carrying its expert ground-truth lesion mask. The 32-case test split is not included because its ground-truth masks were withheld by the challenge organizers for leaderboard scoring (image-only, not useful for segmentation evaluation).

Contents

• 43 training cases (training_1 … training_48, non-contiguous — IDs 3, 17, 25, 29, 34 are absent).

• 8 NIfTI (.nii) volumes per case, each in its own sub-folder:

  Token	Description	Dim
  MR_4DPWI	Raw 4-D perfusion-weighted source series (40–80 timepoints)	4-D / 5-D
  MR_ADC	Apparent diffusion coefficient map	3-D
  MR_MTT	Mean transit time	3-D
  MR_rCBF	Relative cerebral blood flow	3-D
  MR_rCBV	Relative cerebral blood volume	3-D
  MR_Tmax	Time-to-maximum of the residue function	3-D
  MR_TTP	Time to peak	3-D
  OT	Ground-truth lesion mask (binary 0/1)	3-D

• Perfusion maps were computed by the organizers with Olea Sphere (bSVD deconvolution). All volumes within a case share the same spatial grid and are co-registered to the mask. Spatial grids vary across cases (e.g. 192×192×19, 256×256×24, 128×128×25, 192×192×30).

• Note: the raw MR_4DPWI series is stored 5-D (X, Y, Z, 1, T) for cases using the VSD.* naming and 4-D (X, Y, Z, T) for cases using the SMIR.* naming (squeeze the singleton when present).

Folder / naming convention

training_<N>/<PREFIX>.Brain.XX.O.<TOKEN>.<objectID>/<PREFIX>.Brain.XX.O.<TOKEN>.<objectID>.nii

<PREFIX> is VSD for 30 cases and SMIR for 13 cases (training_36–training_48). A dataloader must match on <TOKEN> (e.g. *.MR_ADC.*, *.OT.*) regardless of prefix, and must enumerate the actual directories rather than assuming a contiguous 1..43 range. The <objectID> in each folder name is the original SMIR/VSD object ID and is preserved here — it is the only cross-year linkage handle (see Overlap below).

Ground truth

The OT volume is the final infarct delineated on the follow-up T2 image by a board-certified neuroradiologist in 3D Slicer. Binary (0 = background, 1 = lesion). All 43 training masks are non-empty (lesion sizes range from a few dozen to ~24 k voxels). This is the single, gold-standard annotation tier; there is no alternative rater set in the public release.

Provenance & license

• Source: organizers' Zenodo deposit DOI 10.5281/zenodo.17736412 (Reyes, de la Rosa, Menze; Nov 2025), released CC BY 4.0. The original official host (SMIR / smir.ch, isles-challenge.org/ISLES2017) is offline as of 2026, so this organizer-authored re-host is the working source.
• The per-folder License_ODC_ODBL.txt files shipped inside the original archive carry an Open Data Commons ODbL notice; the umbrella Zenodo deposit re-licenses the posted files under CC BY 4.0. Attribute the challenge when reusing.
• Case counts match the benchmark paper exactly (43 train / 32 test = 75).

Cross-dataset overlap (evaluation-leakage note)

• ISLES 2017 fully contains ISLES 2016 (it is the 2016 cohort extended by 8 train + 13 test cases). Never benchmark 2016 and 2017 as independent sets.
• Independent of Angelou0516/isles2022 and Angelou0516/isles2024 — those are newer, separate multi-center cohorts with no documented patient overlap.
• There is no official cross-year patient-ID crosswalk; the SMIR/VSD object ID embedded in folder names is the only handle and is shared only between the 2016 and 2017 editions.

Citation

Winzeck S, Hakim A, McKinley R, et al. ISLES 2016 and 2017 — Benchmarking Ischemic Stroke Lesion Outcome Prediction Based on Multispectral MRI. Frontiers in Neurology 2018;9:679. doi:10.3389/fneur.2018.00679

Please also cite the data via its Zenodo DOI 10.5281/zenodo.17736412.