Abstract
We develop a customized initialization method for 3D Gaussian Splatting methods, aimed at extending its application to Computed Tomography (CT) reconstruction. Initialization in 3D Gaussian Splatting is a crucial step and can be accomplished using several techniques. The official pipeline of 3D Gaussian Splatting uses the Structure-from-Motion (SfM) technique in its initialization step. While SfM works well for natural scene photographs, it is not directly applicable in the medical domain, more specifically in the CT environment. To address this limitation, we propose a customized, geometricaware initialization method that is compatible with parallel beam CT geometry. We investigated 16 simulated CT datasets along with the Shepp-Logan phantom. These simulated models were acquired from TomoPhantom toolbox that provided 2D projection images as the ground truth. These ground truth images and the 3D models were used in our customized 3D Gaussian placement strategy, ensuring accurate camera orientation and 3D point sampling for parallel-beam CT reconstruction. We obtained the rendered images corresponding to their ground truth projections that mostly preserved the true geometric structures. For the Shepp-Logan phantom, we achieved a test PSNR of 29.987 and an L1 loss of 0.015 after 30,000 iterations. Further work may extend this approach to real-time CT data with different scanner acquisition, such as cone beam or helical.