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Theory of nonexponential NMR signal decay in liver with iron overload or superparamagnetic iron oxide particles
Author(s) -
Jensen J.H.,
Chandra R.
Publication year - 2002
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.10170
Subject(s) - hemosiderosis , hemochromatosis , iron oxide , hereditary hemochromatosis , nuclear magnetic resonance , chemistry , superparamagnetism , magnetic field , physics , pathology , magnetization , biology , medicine , organic chemistry , quantum mechanics , genetics
A quantitative theory is proposed for the nonexponential NMR proton signal decay observed in liver with iron overload or superparamagnetic iron oxide particles. This effect occurs for Carr‐Purcell‐Meiboom‐Gill (CPMG) sequences and is argued to be a direct consequence of the strong magnetic field inhomogeneities generated by the iron, rather than being due to tissue compartments. An approximate mathematical form is given for the signal decay, which is fit to experimental data for samples of rat liver with iron oxide particles, for samples of marmoset liver with hemosiderosis, and for in vivo human liver with hereditary hemochromatosis. The fitting parameters obtained are consistent with the pattern of iron deposition determined from histology. For the case of hereditary hemochromatosis, a good correlation is found between a parameter characterizing the nonexponential decay and the iron concentration. Implications for practical MR quantification of hepatic iron are discussed. Magn Reson Med 47:1131–1138, 2002. © 2002 Wiley‐Liss, Inc.