Premium
Triple‐quantum‐filtered sodium imaging at 9.4 Tesla
Author(s) -
Mirkes Christian,
Shajan G.,
Bause Jonas,
Buckenmaier Kai,
Hoffmann Jens,
Scheffler Klaus
Publication year - 2016
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.25688
Subject(s) - apodization , flip angle , k space , imaging phantom , sensitivity (control systems) , optics , nuclear magnetic resonance , physics , image resolution , materials science , magnetic resonance imaging , electronic engineering , medicine , fourier transform , quantum mechanics , radiology , engineering
Purpose Efficient acquisition of triple‐quantum‐filtered (TQF) sodium images at ultra‐high field (UHF) strength. Methods A three‐pulse preparation and a stack of double‐spirals were used for the acquisition of TQF images at 9.4 Tesla. The flip angles of the TQ preparation were smoothly reduced toward the edge of k‐space along the partition‐encoding direction. In doing so, the specific absorption rate could be reduced while preserving the maximal signal intensity for the partitions most relevant for image contrast in the center of k‐space. Simulations, phantom and in vivo measurements were used to demonstrate the usefulness of the proposed method. Results A higher sensitivity (∼20%) was achieved compared to the standard acquisition without flip angle apodization. Signals from free sodium ions were successfully suppressed irrespective of the amount of apodization used. B 0 corrected TQF images with a nominal resolution of 5 × 5 × 5 mm 3 and an acceptable signal‐to‐noise ratio could be acquired in vivo within 21 min. Conclusion Conventional TQF in combination with flip angle apodization permits to exploit more efficiently the increased sensitivity available at 9.4T. Magn Reson Med 75:1278–1289, 2016. © 2015 Wiley Periodicals, Inc.