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

Area of Science:

• Forensic Medicine
• Radiology
• Pediatric Pathology

Background:

• Postmortem magnetic resonance imaging (PMMRI) is gaining traction in forensic pathology, especially for pediatric cases.
• Current PMMRI protocols may not fully address specific forensic questions.
• Sudden, unexpected infant and child deaths warrant a thorough forensic investigation.

Observation:

• PMMRI protocols should integrate blood-sensitive sequences (T2* and/or susceptibility weighted imaging) to detect or exclude intracranial hemorrhage.
• Postmortem CT (PMCT) should precede PMMRI to identify intracranial air, which can mimic small hemorrhages on MRI.
• A case involving a 3-week-old infant illustrates the importance of this combined imaging approach.

Findings:

• The inclusion of specific MRI sequences enhances the detection of subtle bleeding in postmortem examinations.
• Preceding PMMRI with PMCT is crucial for differentiating air from hemorrhage, improving diagnostic accuracy.
• This approach is vital for accurate determination of cause of death in pediatric cases.

Implications:

• Standardizing PMMRI protocols with forensic considerations can improve the quality of postmortem investigations.
• Educating clinical radiologists, who may interpret these scans without specialized forensic training, is essential.
• Accurate PMMRI interpretation aids in understanding the circumstances of sudden and unexpected deaths in children.