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Signal‐to‐noise ratio for hyperpolarized 3 He MR imaging of human lungs: A 1.5 T and 3 T comparison
Author(s) -
DominguezViqueira William,
Ouriadov Alexei,
O'Halloran Rafael,
Fain Sean B.,
Santyr Giles E.
Publication year - 2011
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.22920
Subject(s) - nuclear magnetic resonance , signal to noise ratio (imaging) , noise (video) , polarizer , field strength , electromagnetic coil , physics , nuclear medicine , chemistry , magnetic field , optics , image (mathematics) , medicine , birefringence , quantum mechanics , artificial intelligence , computer science
The signal‐to‐noise ratio in hyperpolarized noble gas MR imaging is expected to be independent of field strength at frequencies typical of clinical systems (e.g., 1.5 T), where body noise dominates over coil noise. Furthermore, at higher fields (e.g., 3 T), the SNR of lung images may decline due to decreases in T 2 * originating from increases in susceptibility‐induced field gradients at the air‐tissue interface. In this work, the SNR of hyperpolarized 3 He lung imaging at two commonly used clinical field strengths (1.5 T and 3 T) were compared in the same volunteers. Thermally polarized and hyperpolarized 3 He phantoms were used to account for differences in MR imaging system and 3 He polarizer performance, respectively, at the two field strengths. After correcting for T 2 * values measured at 1.5 T (16 ± 2 ms) and 3 T (7 ± 1 ms), no significant difference in image SNR between the two field strengths was observed, consistent with theory. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.