title: Slice encoding for metal artifact correction with noise reduction.
abstract: Magnetic resonance imaging (MRI) near metallic implants is often hampered by severe metal artifacts. To obtain distortion-free MR images near metallic implants, SEMAC (Slice Encoding for Metal Artifact Correction) corrects metal artifacts via robust encoding of excited slices against metal-induced field inhomogeneities, followed by combining the data resolved from multiple SEMAC-encoded slices. However, as many of the resolved data elements only contain noise, SEMAC-corrected images can suffer from relatively low signal-to-noise ratio. Improving the signal-to-noise ratio of SEMAC-corrected images is essential to enable SEMAC in routine clinical studies. In this work, a new reconstruction procedure is proposed to reduce noise in SEMAC-corrected images. A singular value decomposition denoising step is first applied to suppress quadrature noise in multi-coil SEMAC-encoded slices. Subsequently, the singular value decomposition-denoised data are selectively included in the correction of through-plane distortions. The experimental results demonstrate that the proposed reconstruction procedure significantly improves the SNR without compromising the correction of metal artifacts.
authors.affiliation: School of Electrical and Electronic Engineering, Division of Information Engineering, Nanyang Technological University, Singapore. wenmiao.lu@gmail.com
authors.forename: Wenmiao
authors.initials: W
authors.lastname: Lu
authors.forename: Kim B
authors.initials: KB
authors.lastname: Pauly
authors.forename: Garry E
authors.initials: GE
authors.lastname: Gold
authors.forename: John M
authors.initials: JM
authors.lastname: Pauly
authors.forename: Brian A
authors.initials: BA
authors.lastname: Hargreaves
mesh_terms: D016477:Artifacts; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008670:Metals; D019047:Phantoms, Imaging; D019736:Prostheses and Implants; D012785:Shoulder Joint
chemical_list: D008670:Metals