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Temperature‐induced changes of magnetic resonance relaxation times in the human brain: A postmortem study
Author(s) -
Birkl Christoph,
Langkammer Christian,
Haybaeck Johannes,
Ernst Christina,
Stollberger Rudolf,
Fazekas Franz,
Ropele Stefan
Publication year - 2014
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.24799
Subject(s) - relaxometry , magnetic resonance imaging , nuclear magnetic resonance , postmortem changes , magnetization transfer , human brain , relaxation (psychology) , white matter , spin–lattice relaxation , chemistry , materials science , nuclear medicine , spin echo , medicine , physics , pathology , radiology , nuclear quadrupole resonance , psychiatry
Purpose Magnetic resonance relaxation times of most tissues are expected to depend on temperature, which can impact findings in postmortem magnetic resonance imaging or when using magnetic resonance imaging for relaxation‐based thermometry. The purpose of this study was to investigate the exact temperature dependency of the relaxation times T 1 , T 2 , T 2 *, and the magnetization transfer ratio in different structures of the human brain. Methods To prevent fixation and autolysis effects, this study was performed with fresh postmortem brain tissues. Following autopsy, coronal brain slices from five deceased subjects were subjected to relaxometry at 3T in a temperature range between 4°C and 37°C. Heating of the tissue was achieved by flushing the vacuum packed brain slices with water at a predefined temperature. Results T 1 showed a linear dependency on temperature with the highest temperature coefficient in the cortex (17.4 ms/°C) and the lowest in the white matter (3.4 ms/°C). T 2 did not depend on temperature. T 2 * and magnetization transfer ratio scaled with temperature only in deep gray matter. Conclusion The temperature coefficient for T 1 is higher than expected from previous reports and varies across brain structures. The coefficients obtained in this study can serve as reference for thermometry or for correcting quantitative postmortem magnetic resonance imaging. Magn Reson Med 71:1575–1580, 2014. © 2013 Wiley Periodicals, Inc .