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In vivo regional ventilation mapping using fluorinated gas MRI with an x‐centric FGRE method
Author(s) -
Ouriadov Alexei V.,
Fox Matthew S.,
Couch Marcus J.,
Li Tao,
Ball Iain K.,
Albert Mitchell S.
Publication year - 2015
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.25406
Subject(s) - imaging phantom , ventilation (architecture) , sulfur hexafluoride , scanner , lung , in vivo , materials science , chemistry , nuclear medicine , pulse (music) , pulse sequence , inert gas , biomedical engineering , nuclear magnetic resonance , medicine , physics , optics , composite material , thermodynamics , microbiology and biotechnology , organic chemistry , detector , biology
Purpose Inert fluorinated gas lung MRI is a new and promising alternative to hyperpolarized gas lung MRI; it is less expensive and does not require expensive isotopes/polarizers. The thermally polarized nature of signal obtained from fluorinated gases makes it relatively easy to use for dynamic lung imaging and for obtaining lung ventilation maps. In this study, we propose that the sensitivity and resolution of fluorine‐19 ( 19 F) in vivo images can be improved using the x‐centric pulse sequence, thereby achieving a short echo time/pulse repetition time. This study is a transitional step for converting to more sustainable gases for lung imaging. Methods A 19 F‐resolution phantom was used to validate the efficiency of performing the x‐centric pulse sequence on a clinical scanner. Ventilation maps were obtained in the lungs of five normal rats with a washout approach (adapted from Xe‐enhanced computed tomography [Xe‐CT] regional ventilation mapping), using mixtures of either sulfur hexafluoride/oxygen or perfluoropropane/oxygen and a two‐breath x‐centric method. Results Fractional ventilation ( r ) values obtained in this study (0.35–0.46 interval) were in good agreement with previously published values for 3 He/ 129 Xe. Calculated r gradients agreed well with published gradients obtained in rats with Xe‐CT measurements. Conclusions These results suggest that fluorinated gases can be reliably used in vivo in dynamic lung studies as an alternative to 3 He/ 129 Xe. Magn Reson Med 74:550–557, 2015. © 2014 Wiley Periodicals, Inc.