title: Measurement of regional brain temperature using proton spectroscopic imaging: validation and application to acute ischemic stroke.
abstract: A magnetic resonance proton spectroscopic imaging (SI) technique was developed to measure regional brain temperatures in human subjects. The technique was validated in a homogeneous phantom and in four healthy volunteers. Simulations and calculations determined the theoretical measurement precision as approximately +/-0.3 degrees C for individual 1-ml voxels. In healthy volunteers, repeated measurements on individual voxels had an S.D. = 1.2 degrees C. In a clinical study, 40 patients with acute ischemic stroke were imaged within 26 h (mean, 10 h) of onset. Temperatures were highest in the region that appeared abnormal (i.e., ischemic) on diffusion-weighted imaging (DWI) compared with a normal-appearing brain. The mean temperature difference between the DWI "lesion" area and the "normal brain" was 0.17 degrees C [P < 10(-3); range, 2.45 degrees C (hotter)-2.17 degrees C (cooler)]. Noninvasive temperature measurement by SI has sufficient precision to be used in studies of pathophysiology in stroke and in other brain disorders and to monitor therapies.
authors.affiliation: SHEFC Brain Imaging Research Centre for Scotland, University of Edinburgh, Edinburgh, UK. ian.marshall@ed.ac.uk
authors.forename: Ian
authors.initials: I
authors.lastname: Marshall
authors.forename: Bartosz
authors.initials: B
authors.lastname: Karaszewski
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Wardlaw
authors.forename: Vera
authors.initials: V
authors.lastname: Cvoro
authors.forename: Karolina
authors.initials: K
authors.lastname: Wartolowska
authors.forename: Paul A
authors.initials: PA
authors.lastname: Armitage
authors.forename: Trevor
authors.initials: T
authors.lastname: Carpenter
authors.forename: Mark E
authors.initials: ME
authors.lastname: Bastin
authors.forename: Andrew
authors.initials: A
authors.lastname: Farrall
authors.forename: Kristin
authors.initials: K
authors.lastname: Haga
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001831:Body Temperature / Q000502:physiology*; D001921:Brain / Q000098:blood supply / Q000378:metabolism; D002545:Brain Ischemia / Q000503:physiopathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D020521:Stroke / Q000503:physiopathology*