Open dataset · CT

TotalSegmentator — Liver Lesions (CT)

842 CT cases with manual liver-lesion segmentations. Real clinical oncology cohort.

No download, no account needed for the demo case — it opens read-only in the MedSeg editor. Sign up (free) to browse all 842 cases, run AI models, and segment.

CT 842 cases CC-BY-4.0 Reference masks Pathology
TotalSegmentator — Liver Lesions (CT) — example case rendered in the MedSeg editor
Example case with its reference segmentation — straight from the catalog, rendered by MedSeg.

Browse cases

Demo cases open instantly in the browser-based editor — scroll the slices, inspect the reference masks, window the image. Everything else is one free account away.

About this dataset

TotalSegmentator Liver Lesions — 842 CT cases with manual liver lesion segmentations (HCC, metastases, and other focal liver lesions). Wasserthal et al. 2026 training dataset for the TS liver-lesion subtask model. Real clinical oncology data from University Hospital Basel and partner sites. nnU-Net v2 format.

FactValue
Cases842
Series842
Size39.0 GB
ModalityCT
Reference masksYes
LicenseCC-BY-4.0
PublisherUniversity Hospital Basel
Version2026-05
DOI10.5281/zenodo.20272572

What you can do with it in MedSeg

Copied cases behave like normal project series — the public image bytes are linked, not duplicated, so copies are instant and take no extra storage.

  1. Copy cases into a project.
    Filter, multi-select, copy — reference masks come along if you want them.
  2. Run AI segmentation.
    TotalSegmentator, MRSegmentator, nnInteractive 3D clicks/scribbles, or text-prompted VoxTell.
  3. Edit and measure.
    Brush, lasso, fill, oblique planes, volumes in ml — in the browser.
  4. Train your own nnU-Net.
    Correct masks on a handful of cases and train a custom model on hosted GPUs.

Citation

If you use this dataset in your research, cite the source per its license terms.

Wasserthal, J., et al. (2026). TotalSegmentator subtask training datasets. Zenodo.

License: CC-BY-4.0

Open data still carries obligations — attribution at minimum. Check the license terms and the source publication before publishing work built on this dataset. MedSeg is a research tool, not a medical device.

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