title: Characteristic signal intensity changes on postmortem magnetic resonance imaging of the brain.
abstract: OBJECTIVE
  We investigated and identified postmortem changes on magnetic resonance imaging (MRI) of the brain to provide accurate diagnostic guidelines.
  
  
  METHODS
  Our subjects were 16 deceased patients (mean age 57 years) who underwent postmortem computed tomography (CT), MRI, and autopsy, the latter of which showed no abnormalities in the brain. The subjects underwent CT and MRI 6-73 h after confirmation of death (mean 26 h), after being kept in cold storage at 4 degrees C. Postmortem MRI of the brain was performed using T1-weighted imaging (T1WI), T2WI, fluid attenuated inversion recovery (FLAIR) imaging, and diffusion weighted imaging (DWI) with parameters identical to those used for living persons.
  
  
  RESULTS
  In all cases, postmortem CT showed brain edema and swelling. Postmortem MRI showed characteristic common signal intensity (SI) changes, including (1) high SI of the basal ganglia and thalamus on T1WI; (2) suppression of fat SI on T2WI; (3) insufficient SI suppression of cerebrospinal fluid on FLAIR imaging; (4) high SI rims along the cerebral cortices and the ventricular wall on DWI; and (5) an apparent diffusion coefficient decrease to less than half the normal value.
  
  
  CONCLUSIONS
  Postmortem MRI of the brain in all cases showed characteristic common SI changes. Global cerebral ischemia without following reperfusion and low body temperature explain these changes.
authors.affiliation: Department of Radiological Technology, Tsukuba Medical Center, 1-3-1 Amakubo, Tsukuba, Japan. t.kobayashi1001@gmail.com
authors.forename: Tomoya
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Seiji
authors.initials: S
authors.lastname: Shiotani
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kaga
authors.forename: Hajime
authors.initials: H
authors.lastname: Saito
authors.forename: Kousaku
authors.initials: K
authors.lastname: Saotome
authors.forename: Katsumi
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Mototsugu
authors.initials: M
authors.lastname: Kohno
authors.forename: Kazunori
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Hayakawa
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Homma
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology*; D001929:Brain Edema / Q000000981:diagnostic imaging / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011180:Postmortem Changes; D012815:Signal Processing, Computer-Assisted; D014057:Tomography, X-Ray Computed