Puzzling over intracranial gas: Disclosing a pitfall on postmortem computed tomography in a case of fatal blunt trauma

We report a case of unusual intracranial gas distribution after fatal blunt force trauma to the chest. After a first cursory review of the post-mortem computed tomography (PMCT) images, the intracranial gas collection was misinterpreted as intraarterial air embolism. A second, more thorough review of the findings revealed an exclusive intra-thecal distribution of the gas, resulting in a pseudo-cisternography. This rare pattern was explained by the presence of a traumatic injury to the thoracic spine which had caused an open passage between the thoracic cavity and the spinal canal. Air had ascended to the non-injured, intact skull and filled the intra-thecal space. This case serves as a reminder that PMCT images should always be reviewed carefully and thoroughly. It is not sufficient to focus on major findings or skeletal injuries only. Subtle findings may often prove vital to establishing the cause of death.