About MedSeg
MedSeg is a web application for visualising and segmenting three-dimensional medical images: CT, MRI, and other DICOM volumes. It runs entirely in the browser, with AI inference and custom model training executed on hosted GPUs. It is built and maintained by a small team of radiologists in Oslo, Norway, for other radiologists and researchers. The project's roots go back several years.
Two MedSegs, one team
This site, app.medseg.ai, is the newer multi-user platform: shared projects, hosted AI inference, custom model training, optional PACS integration. The older single-user tool is still available, free and without an account, at medseg.ai. They use the same segmentation engine; the multi-user platform adds collaboration, bigger models, and longer pipelines.
Signing up
Getting in is self-service. Sign in with Google and you're straight into the app. Sign up with an email and password instead and you just confirm your email address with a link we send you - then you're in. There's no waiting list and no one approving accounts by hand.
You can also look before you sign up: open a sample case in the editor, or browse the public datasets and open a case from there.
If you'd rather try MedSeg with no account at all, medseg.ai works in any modern browser today.
What's on the platform
- Pretrained AI models covering CT and MRI: TotalSegmentator, MRSegmentator, FastSurfer, MindGlide, TissUNet, Viola-Unet, BodySegAI, plus a specialty pack for epilepsy work (MELD, AID-HS, nnU-Net FCD, DeepFCD). Happy to add more on request.
- nnInteractive: universal 3-D interactive segmentation, driven by clicks, scribbles, freehand strokes, or bounding boxes.
- Custom nnU-Net training (2-D or 3-D), with optional transfer learning from another model you've already trained in the same project.
- A built-in chat assistant that runs models on demand, summarises series, and answers how-to questions.
- DICOM and NIfTI throughout: you upload either, and you can export masks back as either, including DICOM SEG and PDF reports for PACS routing.
- X-ray and mammography: single-frame DICOMs (chest X-ray, mammography, panoramic dental) load and can be edited, measured, and used for custom 2-D nnU-Net training. The bundled 3-D AI models don't apply to them.
- Phones and tablets: the workspace is responsive and usable on touchscreens, not just desktops.
- VR and AR viewer: open any segmented series in an immersive 3-D viewer powered by WebXR. Works on Meta Quest and similar devices.
Free for research
This cloud platform (app.medseg.ai) is free of charge for personal, academic, and non-commercial research, under the bundled MedSeg Software License.
Commercial and on-premise use
For for-profit clinical services, hosted commercial offerings, or an on-premise install on your own hardware, we offer a separate commercial product. It ships under different terms with a different bundled feature set. Write to us if that's what you need.
Not a medical device
MedSeg is a research tool. It has not been cleared, approved, certified, or registered by the FDA, EMA, MHRA, Health Canada, or any other regulator, and it does not carry a CE mark. Do not use it for any clinical, diagnostic, prognostic, screening, or treatment decision concerning a patient. See the full Terms of Service and Privacy Policy.
How to reach us
The fastest channel is the envelope icon inside the in-app assistant once you're signed in. It opens a short form (Bug / Feature idea / Question / Other) with the option to attach the current conversation as context. From outside the app:
- Email: dlinradiology@gmail.com
- Contact form on medseg.ai
- LinkedIn: linkedin.com/company/medsegmentation
- YouTube: youtube.com/channel/UCSexzngll7DQoVo923iBjNA
- Twitter / X: @DLinRadiology
Citing MedSeg
If MedSeg helps a paper or project, a reference to medseg.ai is appreciated.