Dual Domain Diffusion Guidance for 3D CBCT Metal Artifact Reduction

Yongjin Choi, Doeyoung Kwon, Seung Jun Baek; Proceedings of the IEEE/CVF Winter Conference on Applications of Computer Vision (WACV), 2024, pp. 7965-7974

Previous methods to solve the problem of metal artifact reduction (MAR) have mostly focused on 2D MAR, making it challenging to apply to problems with 3-dimensional CT such as CBCT. In this paper, we propose a novel approach for 3D MAR which utilizes two diffusion models to model the metal-free CBCT prior and metal artifact prior. Through dual-domain guidance in the image and projection domains, the 3D connectivity is enhanced in the restored images. Moreover, we propose a memory-efficient technique for an efficient sampling of 3-dimensional data, which reduces the memory usage by orders of magnitude. Experiments show that our method achieves the state-of-the-art performance not only with synthetic data but also with real-world clinical and out-of-distribution data.