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High‐resolution magnetization‐prepared 3D‐FLAIR imaging at 7.0 Tesla
Author(s) -
Visser Fredy,
Zwanenburg Jaco J. M.,
Hoogduin Johannes M.,
Luijten Peter R.
Publication year - 2010
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.22397
Subject(s) - fluid attenuated inversion recovery , nuclear magnetic resonance , magnetization , magnetization transfer , magnetic resonance imaging , resolution (logic) , nuclear medicine , physics , materials science , medicine , radiology , computer science , magnetic field , artificial intelligence , quantum mechanics
The aim of the present study is to develop a submillimeter volumetric (three‐dimensional) fluid‐attenuated inversion recovery sequence at 7T. Implementation of the fluid‐attenuated inversion recovery sequence is difficult as increased T 1 weighting from prolonged T 1 constants at 7T dominate the desired T 2 contrast and yield suboptimal signal‐to‐noise ratio. Magnetization preparation was used to reduce T 1 weighting and improve the T 2 weighting. Also, practical challenges limit the implementation. Long refocusing trains with low flip angles were used to mitigate the specific absorption rate constraints. This resulted in a three‐dimensional magnetization preparation fluid‐attenuated inversion recovery sequence with 0.8 × 0.8 × 0.8 = 0.5 mm 3 resolution in a clinically acceptable scan time. The contrast‐to‐noise ratio between gray matter and white matter (contrast‐to‐noise ratio = signal‐to‐noise ratio [gray matter] − signal‐to‐noise ratio [white matter]) increased from 12 ± 9 without magnetization preparation to 28 ± 8 with magnetization preparation ( n = 12). The signal‐to‐noise ratio increased for white matter by 13 ± 6% and for gray matter by 48 ± 15%. In conclusion, three‐dimensional fluid‐attenuated inversion recovery with high resolution and full brain coverage is feasible at 7T. Magnetization preparation reduces the T 1 weighting, thereby improving the T 2 weighted contrast and signal‐to‐noise ratio. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.