🤖 AI Summary
This work addresses the challenge of severe artifacts in computed tomography (CT) reconstruction under highly sparse angular sampling and dynamic motion. To this end, we propose a geometry-aware Gaussian deformation reconstruction framework that integrates multi-resolution hash encoding, time-conditioned Gaussian representations, and a spatiotemporal attention mechanism. The method further incorporates geometric prior regularization and a respiratory motion flow network to effectively model both static anatomical structures and dynamic deformations. Extensive experiments on synthetic and real-world datasets demonstrate that our approach significantly outperforms existing methods, achieving high-fidelity and temporally consistent CT reconstructions even under ultra-sparse viewing conditions.
📝 Abstract
3D Gaussian Splatting (3DGS) has revolutionized 3D scene representation with superior efficiency and quality. While recent adaptations for computed tomography (CT) show promise, they struggle with severe artifacts under highly sparse-view projections and dynamic motions. To address these challenges, we propose Tomographic Geometry Field (TG-Field), a geometry-aware Gaussian deformation framework tailored for both static and dynamic CT reconstruction. A multi-resolution hash encoder is employed to capture local spatial priors, regularizing primitive parameters under ultra-sparse settings. We further extend the framework to dynamic reconstruction by introducing time-conditioned representations and a spatiotemporal attention block to adaptively aggregate features, thereby resolving spatiotemporal ambiguities and enforcing temporal coherence. In addition, a motion-flow network models fine-grained respiratory motion to track local anatomical deformations. Extensive experiments on synthetic and real-world datasets demonstrate that TG-Field consistently outperforms existing methods, achieving state-of-the-art reconstruction accuracy under highly sparse-view conditions.