Postmortem 24-h interval computed tomography findings on intrahepatic gas development and changes of liver parenchyma radiopacity.

PURPOSE: The purpose of this study was to assess and analyze the development of intrahepatic gas and its distribution over time as well as radiopacity changes of the liver parenchyma after non-traumatic death during a period of 24h using postmortem computed tomography (PMCT).
MATERIALS AND METHODS: Five male corpses (age range 24-64 yrs) who had died for any other reason than trauma were enrolled in this study. Whole body multi detector row computed tomography (MDCT) scans (Brilliance 64-channel, Philips, Amsterdam, NL) were performed for 24 h with one examination per hour. At an average of 6h after the corpses were found on scene the first CT-exam took place. For the analysis of the intrahepatic gas development and distribution within 24h after death the liver was virtually divided into four parts. Each examination was analyzed for gas bubbles and the possible increase over time using a semiquantitative/visual assessment employing a four-grade scale. The changes of the radiopacity of the liver parenchyma were assessed in a similar way. In each of the four parts of the liver three regions of interest of the same size were placed and recorded over time. Three radiologists and one coroner independently performed the analysis of the gas development and radiopacity changes.
RESULTS: In two corpses the amount of gas and its distribution did not change over the observation period whereas in the other three corpses the gas content increased within the first four to seven hours and was most pronounced in the left liver lobe and least in the right posterior liver lobe. In all five corpses the radiopacity of the liver parenchyma did not change significantly over time with the highest radiopacity in the right posterior liver lobe. Good interobserver reliability concerning the assessment of intrahepatic gas accumulation was found. DISCUSSION: Our results indicate that PMCT is useful to detect intrahepatic gas. However, several reasons for these findings besides putrefaction e.g. trauma, resuscitation exist. For an elucidation of the exact causation of the gas accumulation further studies are required with longer postmortem examination times (24-72 h) to detect more pronounced changes of gas and organ radiopacity but also an earlier start of examination after death is desirable. Moreover, it has to be elucidated whether other organs exhibit a similar behavior and how temperature of the CT-room and the body impacts on these parameters.