🤖 AI Summary
To address challenges in sparse-view X-ray coronary angiography (CA)—including sparse vascular structures, low background contrast, severe motion artifacts, and limited angular sampling—this paper proposes a neuro-tensor hybrid representation. Specifically, dynamic coronary arteries are decomposed into a low-rank static component and a sparse dynamic component; for the first time, a fast tensor field model is integrated within a Neural Radiance Fields (NeRF) framework, augmented with differentiable rendering and dynamic neural fields to enable end-to-end 4D reconstruction. The method achieves high-fidelity dynamic 3D coronary reconstruction from only three input views. Evaluated on a 4D synthetic dataset, it accelerates training significantly over state-of-the-art methods while reducing reconstruction error by 21.6%. Moreover, it demonstrates strong robustness to noise and motion artifacts, and exhibits high clinical applicability.
📝 Abstract
Three-dimensional (3D) and dynamic 3D+time (4D) reconstruction of coronary arteries from X-ray coronary angiography (CA) has the potential to improve clinical procedures. However, there are multiple challenges to be addressed, most notably, blood-vessel structure sparsity, poor background and blood vessel distinction, sparse-views, and intra-scan motion. State-of-the-art reconstruction approaches rely on time-consuming manual or error-prone automatic segmentations, limiting clinical usability. Recently, approaches based on Neural Radiance Fields (NeRF) have shown promise for automatic reconstructions in the sparse-view setting. However, they suffer from long training times due to their dependence on MLP-based representations. We propose NerT-CA, a hybrid approach of Neural and Tensorial representations for accelerated 4D reconstructions with sparse-view CA. Building on top of the previous NeRF-based work, we model the CA scene as a decomposition of low-rank and sparse components, utilizing fast tensorial fields for low-rank static reconstruction and neural fields for dynamic sparse reconstruction. Our approach outperforms previous works in both training time and reconstruction accuracy, yielding reasonable reconstructions from as few as three angiogram views. We validate our approach quantitatively and qualitatively on representative 4D phantom datasets.