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Long echo time proton magnetic resonance spectroscopy for estimating relative measures of lipid unsaturation at 3 T
Author(s) -
Troitskaia Alice,
Fallone B. Gino,
Yahya Atiyah
Publication year - 2013
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.23868
Subject(s) - degree of unsaturation , methylene , chemistry , proton magnetic resonance , nuclear magnetic resonance , analytical chemistry (journal) , chromatography , organic chemistry , physics
Purpose: To examine the behavior of lipid olefinic and diallylic resonances as a function of PRESS (point resolved spectroscopy) echo time (TE) to determine an optimal long TE value for their measurement at 3 T. Materials and Methods: Experiments were conducted on nine oils (almond, canola, cod liver, corn, linseed, peanut, sesame, sunflower, and walnut oil) and on vertebral and tibial bone marrow in vivo at 3 T. The methylene (or methyl + methylene), diallylic, and olefinic resonances were measured with PRESS with multiple TEs. Results: J‐coupling evolution effects on the olefinic and diallylic peaks appeared to be minimized when TE = 200 msec. The TE = 200 msec olefinic/methylene and diallylic/methylene peak area ratios calculated for each oil correlated well with ratios deduced from oil compositions in the literature (R 2 = 0.92 and 0.98 for the olefinic and diallylic protons, respectively). In addition, the relative amounts of bone marrow unsaturation of vertebral and tibial bone marrow inferred from the TE = 200 msec olefinic/(methyl + methylene) peak area ratio agreed with values estimated from the literature. Conclusion: A PRESS sequence with a long TE value of 200 msec is suitable for determining relative amounts of lipid unsaturation at 3 T. J. Magn. Reson. Imaging 2013;37:944–949. © 2012 Wiley Periodicals, Inc.