title: Cone Beam X-ray Luminescence Computed Tomography Based on Bayesian Method.
abstract: X-ray luminescence computed tomography (XLCT), which aims to achieve molecular and functional imaging by X-rays, has recently been proposed as a new imaging modality. Combining the principles of X-ray excitation of luminescence-based probes and optical signal detection, XLCT naturally fuses functional and anatomical images and provides complementary information for a wide range of applications in biomedical research. In order to improve the data acquisition efficiency of previously developed narrow-beam XLCT, a cone beam XLCT (CB-XLCT) mode is adopted here to take advantage of the useful geometric features of cone beam excitation. Practically, a major hurdle in using cone beam X-ray for XLCT is that the inverse problem here is seriously ill-conditioned, hindering us to achieve good image quality. In this paper, we propose a novel Bayesian method to tackle the bottleneck in CB-XLCT reconstruction. The method utilizes a local regularization strategy based on Gaussian Markov random field to mitigate the ill-conditioness of CB-XLCT. An alternating optimization scheme is then used to automatically calculate all the unknown hyperparameters while an iterative coordinate descent algorithm is adopted to reconstruct the image with a voxel-based closed-form solution. Results of numerical simulations and mouse experiments show that the self-adaptive Bayesian method significantly improves the CB-XLCT image quality as compared with conventional methods.
authors: Guanglei
authors: G
authors: Zhang
authors: Fei
authors: F
authors: Liu
authors: Jie
authors: J
authors: Liu
authors: Jianwen
authors: J
authors: Luo
authors: Yaoqin
authors: Y
authors: Xie
authors: Jing
authors: J
authors: Bai
authors: Lei
authors: L
authors: Xing
mesh_terms: D000465:Algorithms; D000818:Animals; D001499:Bayes Theorem; D054893:Cone-Beam Computed Tomography; D007091:Image Processing, Computer-Assisted; D049449:Luminescence; D051379:Mice; D019047:Phantoms, Imaging; D014057:Tomography, X-Ray Computed; D014965:X-Rays