title: Intrahepatic gas at postmortem computed tomography: forensic experience as a potential guide for in vivo trauma imaging.
abstract: BACKGROUND
  Until August 2004 there were 106 forensic cases examined with postmortem multislice computed tomography (MSCT) and magnetic resonance (MR) imaging before traditional autopsy within the Virtopsy project. Intrahepatic gas (IHG) was a frequent finding in postmortem MSCT examinations. The aim of this study was to investigate its cause and significance.
  
  
  METHODS
  There were 84 virtopsy cases retrospectively investigated concerning the occurrence, location, and volume of IHG in postmortem MSCT imaging (1.25 mm collimation, 1.25 mm thickness). We assessed and noted the occurrence of intestinal distention, putrefaction, and systemic gas embolisms and the cause of death, possible open trauma, possible artificial respiration, and the postmortem interval. We investigated the relations between the findings using the contingency table (chi2 test) and the comparison of the postmortem intervals in both groups was performed using the t test in 79 nonputrefied corpses.
  
  
  RESULTS
  IHG was found in 47 cases (59.5%). In five of the cases, the IHG was caused or influenced by putrefaction. Gas distribution within the liver of the remaining 42 cases was as follows: hepatic arteries in 21 cases, hepatic veins in 35 cases, and portal vein branches in 13 cases; among which combinations also occurred in 20 cases. The presence of IHG was strongly related to open trauma with systemic gas. Pulmonary barotrauma as occurring under artificial respiration or in drowning also caused IHG. Putrefaction did not seem to influence the occurrence of IHG until macroscopic signs of putrefaction were noticeable.
  
  
  CONCLUSIONS
  IHG is a frequent finding in traumatic causes of death and requires a systemic gas embolism. Exceptions are putrefied or burned corpses. Common clinical causes such as necrotic bowel diseases appear rarely as a cause of IHG in our forensic case material.
authors.affiliation: Institute of Forensic Medicine, University of Bern, Switzerland. christian.jackowski@irm.unibe.ch
authors.forename: Christian
authors.initials: C
authors.lastname: Jackowski
authors.forename: Martin
authors.initials: M
authors.lastname: Sonnenschein
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Thali
authors.forename: Emin
authors.initials: E
authors.lastname: Aghayev
authors.forename: Kathrin
authors.initials: K
authors.lastname: Yen
authors.forename: Richard
authors.initials: R
authors.lastname: Dirnhofer
authors.forename: Peter
authors.initials: P
authors.lastname: Vock
mesh_terms: D001344:Autopsy / Q000379:methods*; D001659:Biliary Tract / Q000098:blood supply / Q000737:chemistry*; D005740:Gases / Q000032:analysis*; D006499:Hepatic Artery / Q000737:chemistry; D006503:Hepatic Veins / Q000737:chemistry; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D011180:Postmortem Changes; D012121:Respiration, Artificial; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014947:Wounds and Injuries
chemical_list: D005740:Gases