BodyCompositionCT-ResEncM
BodyCompositionCT-ResEncM is a 3D nnU-Net v2 model for segmenting native
body-composition compartments and supporting anatomical structures in CT. This
is a single-checkpoint ResEnc M model trained on the complete training set. For
five-fold ResEnc L ensemble inference, see
BodyCompositionCT-ResEncL.
Model overview
| Property | Value |
|---|
| Task | Mutually exclusive 3D semantic segmentation |
| Input | One CT volume |
| Architecture | nnU-Net v2, 3d_fullres, ResEnc M |
| Checkpoint | One fold_all model trained on all training cases |
| Training set | 1,656 CT scans |
| Native output | Background plus seven foreground labels |
| License | CC BY 4.0 |
Native output labels
| ID | Label | Description |
|---|
| 0 | Background | |
| 1 | Muscle | Muscle compartment |
| 2 | Bone | Bone |
| 3 | Subcutaneous | Subcutaneous compartment |
| 4 | Abdominal | Abdominal compartment, with organs and larger vessels excluded |
| 5 | Thoracic | Thoracic compartment, with organs and larger vessels excluded |
| 6 | Heart | Heart |
| 7 | Lungs | Lungs |
Labels 1, 3, 4, and 5 denote anatomical compartments rather than final
attenuation-defined tissue masks. The muscle compartment can contain inter- and
intramuscular connective tissue, smaller vessels, and larger fat-attenuation
regions. IMAT is not a separate model class; CT-visible IMAT can be derived
downstream within label 1 using HU-thresholding. All downstream tissue
measurements should state their HU range, cleanup rules, and source compartment.
The machine-readable mapping is stored in
dataset.json.
Training data and target construction
The training set contains 750 CT scans from
SAROS and 906 from the
TotalSegmentator v2 dataset.
Another 332 cases (150 SAROS and 182 TotalSegmentator) were reserved and were
not used for training.
Targets were constructed from dense
BOA Task542 body-region
predictions, sparse expert-reviewed SAROS labels, and TotalSegmentator-derived
anatomical masks. Reviewed SAROS labels replaced predictions on annotated
slices. TotalSegmentator muscle, bone, lung, tracheal, body-trunk, organ,
vessel, and neural masks supplied corrections and exclusions. HU-guided
candidate selection, morphological cleanup, model-assisted completion, and
manual review produced the final seven foreground labels.
Only the open TotalSegmentator total and body tasks were used for target
construction; the separately licensed tissue_types and vertebrae_body
tasks were not used.
Training logs, plans, a configuration snapshot, and the training progress plot
are included with the model.
Inference
The model uses the standard nnU-Net v2 results layout. The commands below were
tested with nnU-Net v2 2.5.2. Input files must be unwindowed CT NIfTI volumes
containing Hounsfield-unit values and named <case>_0000.nii.gz. Do not
normalize or resample them manually; nnU-Net applies the preprocessing stored
in the plans.
For integration with preprocessing and downstream tissue derivation, see the
BodyComposition pipeline.
Set the nnU-Net results directory and download the model:
1export nnUNet_results="/path/to/nnUNet_results"
2
3hf download fhofmann/BodyCompositionCT-ResEncM \
4 --local-dir "${nnUNet_results}/Dataset611_Tissue"
Optionally verify the model artifacts:
1cd "${nnUNet_results}/Dataset611_Tissue"
2sha256sum -c MODEL_ARTIFACTS.sha256
Run inference:
1nnUNetv2_predict \
2 -d Dataset611_Tissue \
3 -i INPUT_FOLDER \
4 -o OUTPUT_FOLDER \
5 -f all \
6 -tr nnUNetTrainer \
7 -c 3d_fullres \
8 -p nnUNetResEncUNetMPlans
No independent nnU-Net postprocessing configuration was selected for this
fold_all model. HU-based tissue derivation remains a separate downstream
step.
The checkpoint is a serialized PyTorch artifact. Load it only from a trusted
copy of this repository.
Evaluation status
The fold_all checkpoint was trained on all 1,656 training cases and therefore
has no held-out training fold. Values in the training logs are optimization
diagnostics, not independent performance estimates.
Intended use and limitations
The model is intended to provide compartment masks for research pipelines,
including downstream body-composition measurements derived with CT attenuation thresholds.
- It is not intended for diagnosis, treatment decisions, or stand-alone
clinical measurement.
- Training targets combine automated segmentations, deterministic corrections,
and manual review; residual source-model and labeling errors can remain.
- Performance may vary across populations, scanners, acquisition protocols,
contrast phases, artifacts, implants, and uncommon anatomy.
- The targets focus on the body trunk; extremity use is out of scope.
- External validation is required for each intended population and
measurement definition.
License and attribution
The trained weights, model documentation, metadata, and included training
records are released under
CC BY 4.0. Reuse requires
appropriate credit, a link to the license, and an indication of changes. See
LICENSE for the attribution format.
Training source data, source annotations, upstream checkpoints, and
third-party software are not redistributed and retain their original terms:
| Upstream material | Role | Terms |
|---|
| SAROS labels and split metadata | Sparse reviewed labels | CC BY 4.0 |
| SAROS source CT scans | Training images | Collection-specific TCIA terms, including restricted, CC BY, and CC BY-NC collections |
| BOA Task542 weights | Dense initial body-region predictions | MIT |
| TotalSegmentator v2 dataset | Training CT scans and anatomical labels | CC BY 4.0 |
TotalSegmentator total and body tasks | Corrections and exclusions | Apache-2.0 |
| nnU-Net v2 | Training framework and architecture | Apache-2.0 |
See
THIRD_PARTY_NOTICES.md for source links and the
complete provenance and license summary.
References
- Hofmann FO et al. Validation of body composition parameters extracted via
deep learning-based segmentation from routine computed tomographies.
Scientific Reports (2025).
https://doi.org/10.1038/s41598-025-96238-6
- Haubold J et al. SAROS: A dataset for whole-body region and organ
segmentation in CT imaging. Scientific Data (2024).
https://doi.org/10.1038/s41597-024-03337-6
- Haubold J et al. BOA: A CT-Based Body and Organ Analysis for Radiologists at
the Point of Care. Investigative Radiology (2023).
https://doi.org/10.1097/RLI.0000000000001040
- Wasserthal J et al. TotalSegmentator: Robust Segmentation of 104 Anatomic
Structures in CT Images. Radiology: Artificial Intelligence (2023).
https://doi.org/10.1148/ryai.230024
- Isensee F et al. nnU-Net: a self-configuring method for deep
learning-based biomedical image segmentation. Nature Methods (2021).
https://doi.org/10.1038/s41592-020-01008-z
- Isensee F et al. nnU-Net Revisited: A Call for Rigorous Validation in 3D
Medical Image Segmentation. arXiv (2024).
https://doi.org/10.48550/arXiv.2404.09556
Questions and feedback are welcome in the repository's
Community
section.