| --- |
| license: cc-by-nc-nd-4.0 |
| tags: |
| - medical-imaging |
| - ct |
| - vision |
| - vision-language |
| --- |
| |
| # FlexiCT |
|
|
| FlexiCT is a CT foundation model family trained through agglomerative continual pretraining from 2D slice-level anatomy to 3D volumetric reasoning and report-aligned vision-language understanding. |
|
|
| This family page links three child repos: |
|
|
| | Repo | Input | Output | Recommended use | |
| |---|---|---|---| |
| | `ricklisz/FlexiCT-2D` | `[B, 1, 512, 512]` CT slices | CLS and patch tokens | Slice-level feature extraction, classification, visualization, registration features | |
| | `ricklisz/FlexiCT-3D` | `[B, 1, 160, 160, 160]` CT volumes | CLS and patch tokens | Whole-volume feature extraction and downstream 3D workflows | |
| | `ricklisz/FlexiCT-3D-VLM` | CT volumes plus text | Image/text embeddings and similarity scores | Report-aligned retrieval and zero-shot text-image scoring | |
|
|
| ## Preprocessing presets |
|
|
| `default` is recommended for whole-volume 3D and 3D-VLM inference. It orients/resamples path inputs to LPS at 2 mm spacing when spacing is available, clips HU to `[-1000, 1000]`, z-score normalizes, pads with the tensor minimum to at least `160^3`, then center crops to `160^3`. This best matches the released VLM evaluation path because it preserves physical scale better than globally resizing the anatomy. |
|
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| `local_path` is a forgiving demo preset for arbitrary local CT files. It orients/resamples path inputs, clips, normalizes, pads to a cube, then trilinear-resizes to `160^3`. It is robust to heterogeneous scans but less faithful to the VLM inference scripts because it globally rescales anatomy. |
|
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| `retrieval_roi` is retrieval-specific. It orients/resamples, clips, normalizes, crops an ROI cube from coordinates, a mask, or a bounding box, pads if the crop hits an image boundary, then resizes to `160^3`. |
|
|
| ## License |
|
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| The released checkpoints are made available under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. Code is MIT licensed in the source repository. Users must also comply with licenses and usage terms for the original datasets used to train the models. |
|
|
| ## Citation |
|
|
| ```bibtex |
| @misc{li2026universalctrepresentations, |
| title = {Universal CT Representations from Anatomy to Disease Phenotype through Agglomerative Pretraining}, |
| author = {Yuheng Li and Yuan Gao and Haoyu Dong and Yuxiang Lai and Shansong Wang and Mojtaba Safari and James E. Baciak and Xiaofeng Yang}, |
| year = {2026}, |
| eprint = {2605.21906}, |
| archivePrefix = {arXiv}, |
| primaryClass = {cs.CV}, |
| doi = {10.48550/arXiv.2605.21906}, |
| url = {https://arxiv.org/abs/2605.21906} |
| } |
| ``` |
|
|
| ## Medical disclaimer |
|
|
| FlexiCT is for research use only. It is not a medical device and is not a substitute for professional medical judgment. |
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|
