title: Smaller but denser: postmortem changes alter the CT characteristics of subdural hematomas.
abstract: OBJECTIVE
  The aim of this study was to investigate if (1) the volume of subdural hematomas (SDH), midline shift, and CT density of subdural hematomas are altered by postmortem changes and (2) if these changes are dependent on the postmortem interval (PMI).
  
  
  METHODS
  Ante mortem computed tomography (AMCT) of the head was compared to corresponding postmortem CT (PMCT) in 19 adults with SDH. SDH volume, midline shift, and hematoma density were measured on both AMCT and PMCT and their differences assessed using Wilcoxon-Signed Rank Test. Spearman's Rho Test was used to assess significant correlations between the PMI and the alterations of SDH volume, midline shift, and hematoma density.
  
  
  RESULTS
  Mean time between last AMCT and PMCT was 109 h, mean PMI was 35 h. On PMCT mean midline displacement was decreased by 57% (p < 0.001); mean SDH volume was decreased by 38% (p < 0.001); and mean hematoma density was increased by 18% (p < 0.001) in comparison to AMCT. There was no correlation between the PMI and the normalization of the midline shift (p = 0.706), the reduction of SDH volume (p = 0.366), or the increase of hematoma density (p = 0.140).
  
  
  CONCLUSIONS
  This study reveals that normal postmortem changes significantly affect the extent and imaging characteristics of subdural hematoma and may therefore affect the interpretation of these findings on PMCT. Radiologists and forensic pathologists who use PMCT must be aware of these phenomena in order to correctly interpret PMCT findings in cases of subdural hemorrhages.
authors.affiliation: Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Winterthurerstrasse 190/52, 8057, Zurich, Switzerland.
authors.forename: Nicole
authors.initials: N
authors.lastname: Berger
authors.forename: Lars C
authors.initials: LC
authors.lastname: Ebert
authors.forename: Garyfalia
authors.initials: G
authors.lastname: Ampanozi
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Flach
authors.forename: Dominic
authors.initials: D
authors.lastname: Gascho
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Thali
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Ruder
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D002423:Cause of Death; D005260:Female; D006408:Hematoma, Subdural / Q000000981:diagnostic imaging* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011180:Postmortem Changes; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult