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Imaging lungs using inert fluorinated gases
Author(s) -
Kuethe Dean O.,
Caprihan Arvind,
Fukushima Eiichi,
Waggoner R. Allen
Publication year - 1998
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.1910390114
Subject(s) - excitation , relaxation (psychology) , signal (programming language) , nuclear magnetic resonance , free induction decay , inert gas , projection (relational algebra) , transient (computer programming) , magnetic field , chemistry , materials science , magnetic resonance imaging , physics , spin echo , computer science , radiology , medicine , psychology , social psychology , organic chemistry , algorithm , quantum mechanics , programming language , operating system
Rat lungs were imaged by 19 F projection MRI of hexafluoroethane, mixed with 20% oxygen to form the inhaled gas. The 3D image had 700 μm resolution, and the data took 4.3 h to acquire. Free induction decays were collected in the presence of steady magnetic field gradients in 686 different directions. To take advantage of fast relaxation ( T 1 = 5.9 ± 0.2 ms), the repetition time was 5 ms. To eliminate signal loss from magnetic field inhomogeneities, data were collected within 2 ms of spin excitation (from 80 μs to 2 ms after the 42‐μs π/2 pulses). The singular value decomposition of the transform from frequency to time domain was used to obtain projections despite the absence of data during and immediately after the RF pulses. Inert fluorinated gas imaging may be less expensive than polarized noble gas imaging and is appropriate for imaging steadystate rather than transient gas concentrations.