Abstract
Privacy constraints and limited public datasets have hindered progress in 3D medical shape analysis, particularly for complex and highly variable anatomies such as the Left Atrial Appendage (LAA). We present a conditional generative framework that synthesizes realistic 3D LAA shapes controlled by clinically interpretable geometric descriptors. Our pipeline combines a 3D VQ-GAN, which compresses binary voxel volumes into a discrete codebook, with a VQ-Diffusion model that generates novel shapes conditioned on global and local morphological features via cross-attention. Trained and evaluated on datasets of 6,448 and 1,138 cardiac CT scans, respectively, our model achieves strong shape fidelity (HD95 of 1.17 mm for reconstruction) and high conditional controllability, with R2 values exceeding 0.9 for key descriptors such as volume, surface area, flatness, elongation, and ostium dimensions. The framework enables data extensions at an arbitrary scale, with particular utility for downstream tasks such as computational fluid dynamics and morphological studies of stroke risk. Our architecture is general and transferable to other organs with minimal modification.
Links to Paper and Supplementary Materials
Main Paper (Open Access Version): https://papers.miccai.org/miccai-2026-sat/paper/STACOM2026_006.pdf
SharedIt Link: Not yet available
SpringerLink (DOI): Not yet available
Supplementary Material: Not Submitted
Link to Open Review
Open Review Page: https://openreview.net/profile?id=~Bj%C3%B8rn_Hansen1
BibTex
@InProceedings{HanBjø_Conditional_MICCAISAT2026,
author = { Hansen, Bjørn AND Loft, Jonas AND Paulsen, Rasmus R. AND Camara, Oscar AND Kofoed, Klaus F. AND Sørensen, Kristine Aavild},
title = { { Conditional 3D Shape Synthesis of the Left Atrial Appendage via Discrete Latent Diffusion } },
booktitle = {Medical Image Computing and Computer Assisted Intervention -- MICCAI 2026 Workshops and Challenges},
year = {2026},
publisher = {Springer Nature Switzerland},
volume = {LNCS 17267},
month = {pending},
page = {pending}
}