title: Edge-oriented dual-dictionary guided enrichment (EDGE) for MRI-CT image reconstruction.
abstract: In this paper, we formulate the joint/simultaneous X-ray CT and MRI image reconstruction. In particular, a novel algorithm is proposed for MRI image reconstruction from highly under-sampled MRI data and CT images. It consists of two steps. First, a training dataset is generated from a series of well-registered MRI and CT images on the same patients. Then, an initial MRI image of a patient can be reconstructed via edge-oriented dual-dictionary guided enrichment (EDGE) based on the training dataset and a CT image of the patient. Second, an MRI image is reconstructed using the dictionary learning (DL) algorithm from highly under-sampled k-space data and the initial MRI image. Our algorithm can establish a one-to-one correspondence between the two imaging modalities, and obtain a good initial MRI estimation. Both noise-free and noisy simulation studies were performed to evaluate and validate the proposed algorithm. The results with different under-sampling factors show that the proposed algorithm performed significantly better than those reconstructed using the DL algorithm from MRI data alone.
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing, China.|Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Engineering Physics, Tsinghua University, Beijing, China.|Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, China.
authors.forename: Bigong
authors.initials: B
authors.lastname: Wang
authors.affiliation: Biomedical Imaging Center, Department of Biomedical Engineering, Rensselaer Polytechnic Institute, USA.
authors.forename: Ge
authors.initials: G
authors.lastname: Wang
mesh_terms: D000465:Algorithms; D006257:Head / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D000069550:Machine Learning; D008279:Magnetic Resonance Imaging / Q000379:methods*; D064847:Multimodal Imaging / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: MRI-CT Image reconstruction; dictionary learning (DL); dual-dictionary learning (DDL); multimodality