Postmortem computed tomography as an adjunct to autopsy for analyzing fatal motor vehicle crash injuries: Results of a pilot study

Background. Detailed fatal injury data after fatal motor vehicle crashes (MVC) are necessary to improve occupant safety and promote injury prevention. Autopsy remains the principle source of detailed fatal injury data. However, procedure rates are declining because of a range of technical, ethical, and religious concerns. Postmortem computed tomography (PMCT) is a potential alternative or adjunct to autopsy which is increasingly used by forensic researchers. However, there are only limited data regarding the utility of PMCT for analysis of fatal MVC injuries. Methods. We performed whole body PMCT and autopsy on six subjects fatally injured in MVC in a single county in Michigan. All injuries detected by either method were coded using the Abbreviated Injury Scale (AIS). Severe injuries, defined as AIS 3 or higher (AIS 3+), were tallied for each forensic procedure to allow a comparison of relative diagnostic performance. Results: A total of 46 AIS 3+ injuries were identified by autopsy and PMCT for these cases. The addition of PMCT to autopsy increased overall detection of AIS 3+ injuries (all types) by 28%. PMCT detected 27% more AIS 3+ skeletal injuries than autopsy but 25% less soft tissue injuries. Conclusions. Use of PMCT improves the detection of AIS 3+ injuries after fatal MVC compared with isolated use of autopsy and also produces a highly detailed permanent objective record. PMCT appears to improve detection of skeletal injury compared with autopsy but is less sensitive than autopsy for the detection of AIS 3+ soft tissue injuries. Neither autopsy nor PMCT identified all AIS 3+ injuries revealed by the combination of the two methodologies. This suggests that PMCT should be used as an adjunct to autopsy rather than a replacement whenever feasible.