Open AccessThe role of nonlinear gradients in parallel imaging: A k‐space based analysis
Author(s) -
Galiana Gigi,
Stockmann Jason P.,
Tam Leo,
Peters Dana,
Tagare Hemant,
Constable R. Todd
Publication year - 2012
Publication title -
concepts in magnetic resonance part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.229
H-Index - 49
eISSN - 1552-5023
pISSN - 1546-6086
DOI - 10.1002/cmr.a.21243
Subject(s) - nonlinear system , encode , curvilinear coordinates , computer science , azimuth , image resolution , encoding (memory) , physics , topology (electrical circuits) , optics , geometry , algorithm , computer vision , mathematics , artificial intelligence , chemistry , biochemistry , quantum mechanics , combinatorics , gene
Sequences that encode the spatial information of an object using nonlinear gradient fields are a new frontier in MRI, with potential to provide lower peripheral nerve stimulation, windowed fields of view, tailored spatially‐varying resolution, curved slices that mirror physiological geometry, and, most importantly, very fast parallel imaging with multichannel coils. The acceleration for multichannel images is generally explained by the fact that curvilinear gradient isocontours better complement the azimuthal spatial encoding provided by typical receiver arrays. However, the details of this complementarity have been more difficult to specify. We present a simple and intuitive framework for describing the mechanics of image formation with nonlinear gradients, and we use this framework to review some the main classes of nonlinear encoding schemes. © 2012 Wiley Periodicals, Inc. Concepts Magn Reson Part A 40A: 253–267, 2012.