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Imaging cadavers: Cold FLAIR and noninvasive brain thermometry using CSF diffusion
Author(s) -
Tofts Paul S.,
Jackson Jonathan S.,
Tozer Daniel J.,
Cercignani Mara,
Keir Geoffrey,
MacManus David G.,
Ridgway Gerard R.,
Ridha Basil H.,
Schmierer Klaus,
Siddique Durre,
Thornton John S.,
Wroe Stephen J.,
Fox Nick C.
Publication year - 2008
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.21456
Subject(s) - fluid attenuated inversion recovery , nuclear magnetic resonance , in vivo , nuclear medicine , effective diffusion coefficient , diffusion imaging , cadaver , cadaveric spasm , thermometer , cerebrospinal fluid , chemistry , materials science , magnetic resonance imaging , diffusion mri , medicine , pathology , anatomy , radiology , physics , biology , microbiology and biotechnology , quantum mechanics
There is increasing interest in imaging cadavers for noninvasive autopsies for research purposes. However, the temperature is well below that of in vivo imaging, and a variety of interesting ‘cold brain’ effects are observed. At lower temperatures conventional FLAIR sequences no longer produce dark cerebrospinal fluid (CSF); T 1 is reduced from about 4.0 sec in vivo to 1.7 sec at 1°C. The diffusion coefficient (DC) of CSF is much reduced (from 3.1 10 −9 m 2 s −1 in vivo to 1.1 at 1°C). DC values therefore provide a noninvasive thermometer to measure brain core temperature to within 1.0°C. In three cadavers DC values were 1.1–1.5 10 −9 m 2 s −1 , indicating brain core temperatures of 1–10°C, consistent with external thermocouple measurements. An improved inversion time (TI 0 ) can then be found for FLAIR. At 10°C this Cold FLAIR sequence (TI 0 = 1.5 sec) gave black CSF. Expressions for CSF DC and T 1 as a function of temperature were produced. A measurement of CSF DC could be converted directly to temperature and the required TI 0 found. In vitro values of CSF DC were about 1% lower than that of water. Thus, FLAIR imaging can be optimized for cadaveric brains at low and unknown temperatures, thereby improving value for autopsy purposes and facilitating comparisons with in vivo imaging. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.