title: Zigzag sampling for improved parallel imaging.
abstract: Conventional Cartesian parallel MRI methods are limited to the sensitivity variations provided by the underlying receiver coil array in the dimension in which the data reduction is carried out, namely, the phase-encoding directions. However, in this work an acquisition strategy is presented that takes advantage of sensitivity variations in the readout direction, thus improving the parallel imaging reconstruction process. This is achieved by employing rapidly oscillating phase-encoding gradients during the actual readout. The benefit of this approach is demonstrated in vivo using various zigzag-shaped gradient trajectory designs. It is shown that zigzag type sampling, in analogy to CAIPIRINHA, modifies the appearance of aliasing in 2D and 3D imaging, thereby utilizing additional sensitivity variations in the readout direction directly resulting in improved parallel imaging reconstruction performance.
authors.affiliation: Research Center Magnetic-Resonance-Bavaria, Würzburg, Germany. breuer@mr-bavaria.de
authors.forename: Felix A
authors.initials: FA
authors.lastname: Breuer
authors.forename: Hisamoto
authors.initials: H
authors.lastname: Moriguchi
authors.forename: Nicole
authors.initials: N
authors.lastname: Seiberlich
authors.forename: Martin
authors.initials: M
authors.lastname: Blaimer
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Duerk
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*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity