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Mapping the absolute value of M 0 using dipolar field effects
Author(s) -
Gutteridge S.,
Ramanathan C.,
Bowtell 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.10142
Subject(s) - flip angle , weighting , magnetization , relaxation (psychology) , dipole , calibration , nuclear magnetic resonance , field (mathematics) , magnetization transfer , value (mathematics) , chemistry , physics , magnetic field , mathematics , magnetic resonance imaging , statistics , medicine , psychology , social psychology , organic chemistry , quantum mechanics , acoustics , pure mathematics , radiology
The ability to map the spatial variation of the absolute, rather than the relative value of the equilibrium magnetization could be advantageous in many areas of NMR. However, direct measurement of M 0 is usually difficult because of the multiparametric dependence of the NMR signal. Here we propose a technique for mapping the spatial variation of the absolute value of M 0 , independent of relaxation weighting and flip angle calibration. This method, which works best at high field strengths, is based on the effect of the dipolar field due to the nuclear magnetization that is normally neglected in liquid‐state NMR. The experimental implementation of this sequence at 3.0 T is described, and its initial application to the measurement of the water content of brain tissue is outlined. Magn Reson Med 47:871–879, 2002. © 2002 Wiley‐Liss, Inc.