Air bubble artifact: why postmortem brain MRI should always be combined with postmortem CT.

Forensic pathology increasingly uses postmortem magnetic resonance imaging (PMMRI), particularly in pediatric cases. It should be noted that each (sudden and unexpected) death of an infant or child should have a forensic approach as well. Current postmortem imaging protocols do not focus adequately on forensic queries. First, it is important to demonstrate or rule out bleeding, especially in the brain. Thus, when incorporating PMMRI, a blood sensitive sequence (T2* and/or susceptibility weighted imaging (SWI)) should always be included. Secondly, as intracranial air might mimic small focal intracerebral hemorrhages, PMMRI should be preceded by postmortem CT (PMCT) since air is easily recognizable on CT. This will be illustrated by a case of a deceased 3-week-old baby. Finally, note that postmortem scans will often be interpreted by clinical radiologists, sometimes with no specific training, which makes this case report relevant for a broader audience.