title: Determination of regional brain temperature using proton magnetic resonance spectroscopy to assess brain-body temperature differences in healthy human subjects.
abstract: Proton magnetic resonance spectroscopy ((1)H MRS) was used to determine brain temperature in healthy volunteers. Partially water-suppressed (1)H MRS data sets were acquired at 3T from four different gray matter (GM)/white matter (WM) volumes. Brain temperatures were determined from the chemical-shift difference between the CH(3) of N-acetyl aspartate (NAA) at 2.01 ppm and water. Brain temperatures in (1)H MRS voxels of 2 x 2 x 2 cm(3) showed no substantial heterogeneity. The volume-averaged temperature from single-voxel spectroscopy was compared with body temperatures obtained from the oral cavity, tympanum, and temporal artery regions. The mean brain parenchyma temperature was 0.5 degrees C cooler than readings obtained from three extra-brain sites (P < 0.01). (1)H MRS imaging (MRSI) data were acquired from a slice encompassing the single-voxel volumes to assess the ability of spectroscopic imaging to determine regional brain temperature within the imaging slice. Brain temperature away from the center of the brain determined by MRSI differed from that obtained by single-voxel MRS in the same brain region, possibly due to a poor line width (LW) in MRSI. The data are discussed in the light of proposed brain-body temperature gradients and the use of (1)H MRSI to monitor brain temperature in pathologies, such as brain trauma.
authors.affiliation: Division of Medicine and Neurosciences, University of Manchester, Manchester, UK. Charmaine.childs@manchester.ac.uk
authors.forename: Charmaine
authors.initials: C
authors.lastname: Childs
authors.forename: Yrjö
authors.initials: Y
authors.lastname: Hiltunen
authors.forename: Rishma
authors.initials: R
authors.lastname: Vidyasagar
authors.forename: Risto A
authors.initials: RA
authors.lastname: Kauppinen
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism; D001831:Body Temperature; D001921:Brain / Q000502:physiology*; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D011522:Protons; D012016:Reference Values; D014867:Water / Q000032:analysis / Q000378:metabolism
chemical_list: D011522:Protons; D014867:Water; D001224:Aspartic Acid; C000179:N-acetylaspartate