MRI by steering resonance through space. Issue 1 (1st August 2013)

• Record Type: Journal Article
• Authors: Snyder, Angela L. S.; Corum, Curtis A.; Moeller, Steen; Powell, Nathaniel J.; Garwood, Michael
• Is Part Of: Magnetic resonance in medicine. Volume 72:Issue 1(2014:Jul.)
• Page Start: 49
• Page End: 58
• Publication Date: 2013-08-01
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.24888
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm24888-sec-0001" sec-type="section"> <title>Purpose</title> <p>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.</p> </sec> <sec id="mrm24888-sec-0002" sec-type="section"> <title>Methods</title> <p>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.</p> </sec> <sec id="mrm24888-sec-0003" sec-type="section"> <title>Results</title> <p>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.</p> </sec> <sec id="mrm24888-sec-0004" sec-type="section"> <title>Conclusion</title> <p>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. <bold>Magn Reson Med 72:49–58, 2014. © 2013 Wiley Periodicals, Inc.</bold></p> </sec> </abstract>