title: Virtual coil concept for improved parallel MRI employing conjugate symmetric signals.
abstract: A new approach for utilizing conjugate k-space symmetry for improved parallel MRI performance is presented. By generating virtual coils containing conjugate symmetric k-space signals from actual coils, additional image- and coil-phase information can be incorporated into the reconstruction process for parallel acquisition techniques. In that way the reconstruction conditions are improved, resulting in less noise enhancement. In particular in combination with generalized autocalibrating partially parallel acquisitions (GRAPPA), the virtual coil concept represents a practical approach since no explicit spatial phase information is required. In addition, the influence of phase variations originating from the complex receiver coils as well as from the background is investigated. It is shown that there exist background phase distributions yielding an optimized pMRI reconstruction.
authors.affiliation: Department of Radiology, University Hospitals of Cleveland, Case Western Reserve University, Cleveland, Ohio, USA. blaimer@mrbavaria.de
authors.forename: Martin
authors.initials: M
authors.lastname: Blaimer
authors.forename: Marcel
authors.initials: M
authors.lastname: Gutberlet
authors.forename: Peter
authors.initials: P
authors.lastname: Kellman
authors.forename: Felix A
authors.initials: FA
authors.lastname: Breuer
authors.forename: Herbert
authors.initials: H
authors.lastname: Köstler
authors.forename: Mark A
authors.initials: MA
authors.lastname: Griswold
mesh_terms: D000465:Algorithms; D001921:Brain / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014584:User-Computer Interface