title: POCS-enhanced correction of motion artifacts in parallel MRI.
abstract: A new method for correction of MRI motion artifacts induced by corrupted k-space data, acquired by multiple receiver coils such as phased arrays, is presented. In our approach, a projections onto convex sets (POCS)-based method for reconstruction of sensitivity encoded MRI data (POCSENSE) is employed to identify corrupted k-space samples. After the erroneous data are discarded from the dataset, the artifact-free images are restored from the remaining data using coil sensitivity profiles. The error detection and data restoration are based on informational redundancy of phased-array data and may be applied to full and reduced datasets. An important advantage of the new POCS-based method is that, in addition to multicoil data redundancy, it can use a priori known properties about the imaged object for improved MR image artifact correction. The use of such information was shown to improve significantly k-space error detection and image artifact correction. The method was validated on data corrupted by simulated and real motion such as head motion and pulsatile flow.
authors.affiliation: Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA. samsonov@wisc.edu
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Samsonov
authors.forename: Julia
authors.initials: J
authors.lastname: Velikina
authors.forename: Youngkyoo
authors.initials: Y
authors.lastname: Jung
authors.forename: Eugene G
authors.initials: EG
authors.lastname: Kholmovski
authors.forename: Chris R
authors.initials: CR
authors.lastname: Johnson
authors.forename: Walter F
authors.initials: WF
authors.lastname: Block
mesh_terms: D016477:Artifacts; D019416:Head Movements; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D012680:Sensitivity and Specificity