MRISegmentation

TotalSegmentator MRI

TotalSegmentator MRI does organ segmentation on MRI: one AI task outlines 50 structures, including the abdominal organs, bones, large blood vessels and the main back and hip muscles. Other tasks label each vertebra, the eight liver segments or the body outline. The brain is outlined as one whole structure.

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Use TotalSegmentator MRI in your browser: it runs in the cloud. No coding, no installation.

You upload
MRI scan
You get
Outlined structures
Tasks
5
Cost per million voxels
€0.008–0.009

Is it right for your scan?

Intended use

Outlining major organs and structures on MRI for research: measurements across groups of patients, or a first draft that you then correct by hand. Works best on the MRI sequence types it was trained on.

Known limitations

MRI images look different from scanner to scanner and sequence to sequence, so results vary more than on CT. Less accurate on sequences unlike its training scans, with strong motion or metal artefacts, or with an unusual field of view.

Available tasks (5)

Body outline

Body outline and extremity segmentation for MRI.

Vertebrae

Individual vertebra segmentation for MRI images.

After the AI task

Correct the result in your browser, then measure each structure and follow it across your study. See what is measured

Research details

Built by
Tugba Akinci D'Antonoli, Jakob Wasserthal and colleagues, University Hospital Basel, Switzerland. Nalvera.AI runs their published model and is independent of the authors.
Version
2.18.0 · Apache-2.0 · released 23 Aug 2026
Training data
Trained on a multi-sequence MRI dataset (TotalSegmentator MRI, Akinci D'Antonoli et al., Radiology 2025) covering common abdominal/pelvic and whole-body sequences; expert-reviewed annotations. Adult human anatomy.

Citations & references

Questions about TotalSegmentator MRI

How is this different from the authors' web app?

The authors' web app at totalsegmentator.com takes one scan at a time, and uploading there means accepting its terms: the data can be used to improve the model and shared with other parties or the public in anonymized form. Under Nalvera.AI's privacy policy, uploads are used only to deliver your results, unless you opt a task into research and model training. Nalvera.AI takes multiple scans per submission, lets you correct outlines in your browser and records each task's model version. Nalvera.AI's Study Design groups scans by patient, measures each structure's volume, intensity and functional PET and SPECT parameters, tracks them over time, compares patient groups and exports reports.

Other models

Nalvera iSegCT / MRI · Interactive segmentationNalvera’s in-house model for interactive CT and MRI segmentation. Define the structures you need and refine their outlines directly in your browser.MAISI-v2CT / MRI · GenerationGenerate synthetic CT or brain MRI images without an input scan. Choose the image size and anatomy for research dataset creation.MerlinCT · Report generation · AnalysisExplore abdominal CT scans through generated research reports and predicted findings. Includes tasks for estimating five-year disease risk.MOOSE CTCT · SegmentationFocused CT segmentation for heart chambers, lung lobes, muscles, and other anatomical regions.MRSegmentatorMRI / CT · SegmentationSegment 40 organs, vessels, bones, and muscles from the chest to the hips on MRI or CT, with a body composition task for fat and abdominal muscles on MRI.MuscleMap MRIMRI · SegmentationSegment muscles and bones on whole-body MRI scans across different MRI contrasts, with coverage from the neck through the trunk to the legs.NV-Reason-CTCT · Report generationWrite structured chest or abdominal CT reports, or a step-by-step reasoning walkthrough that states its observations and uncertainty.NV-Segment-CTCT · (Interactive) SegmentationNVIDIA’s CT segmentation model: 117 organs, bones, vessels, and muscles in one pass, plus tasks for the airway and the liver vessels.TotalSegmentator CTCT · SegmentationWhole-body and regional CT segmentation, with additional tasks for individual organs, bones, muscles, and vessels.

Citing Nalvera.AI

Please cite the platform alongside the model's own paper.

@misc{nalvera,
  title        = {Nalvera.AI: a cloud platform for medical-imaging AI},
  author       = {{van der Heyden, Brent}},
  year         = {2026},
  howpublished = {\url{https://nalvera.ai}},
  note         = {Model: TotalSegmentator MRI v2.18.0. Accessed YYYY-MM-DD}
}
Research use only — not a medical device. Outputs are not validated for clinical diagnosis or treatment.
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