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MRI by steering resonance through space
Author(s) -
Snyder Angela L. S.,
Corum Curtis A.,
Moeller Steen,
Powell Nathaniel J.,
Garwood Michael
Publication year - 2014
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24888
Subject(s) - computer science , spins , computer vision , physics , amplitude , field (mathematics) , trajectory , artificial intelligence , acoustics , optics , mathematics , astronomy , pure mathematics , condensed matter physics
Purpose This work introduces a technique to excite MR signals locally and to steer this localized region over the object in a spatiotemporal manner. The purpose is to demonstrate the feasibility of MRI with multidimensional spatiotemporal‐encoding in a way that provides the ability to compensate extreme field inhomogeneity. Methods The method is called steering resonance over the object (STEREO). A modulated gradient is applied in concert with a frequency‐modulated pulse to steer a resonant region through space and thus produce sequential excitation and echo formation. Images are reconstructed using exclusively an inverse problem solution. Results Images of phantoms and human brain were produced to demonstrate the feasibility of the STEREO sequence and image reconstruction. Simulations support the postulated capability to compensate for extreme field inhomogeneity. Conclusion STEREO represents a substantial departure from conventional MRI in which spins contained in the sample, slab, or slice are excited synchronously. By exciting spins sequentially along a curved spatial trajectory, STEREO in principle affords a unique opportunity to adjust for spatial variations in static and radiofrequency fields. By adjusting field amplitudes and frequencies in a temporal manner in STEREO, in future works it should be possible to perform MRI with highly inhomogeneous fields. Magn Reson Med 72:49–58, 2014. © 2013 Wiley Periodicals, Inc.