Postmortem computed tomography-based evaluation of brain decomposition: Correlation with postmortem interval and...

Area of Science:

• Forensic science
• Radiology
• Pathology

Background:

• Accurate postmortem interval (PMI) estimation is critical in forensic investigations.
• Postmortem computed tomography (PMCT) offers potential for assessing brain decomposition as a PMI marker.
• Previous research on PMCT for brain decomposition and PMI estimation is limited.

Purpose of the Study:

• To classify and quantify brain decomposition using PMCT findings.
• To investigate the association between brain decomposition, PMI, and cause of death determinability.
• To explore the influence of environmental factors on brain decomposition.

Main Methods:

• Retrospective analysis of 176 adult autopsy cases with preautopsy PMCT.
• Classification of brain decomposition into five stages based on visual PMCT findings.
• Quantification of decomposition using brain area-to-length ratios on axial CT slices.
• Correlation and regression analyses to assess associations between PMI, decomposition, and cause of death.

Main Results:

• Brain decomposition stage and quantitative indices strongly correlated with PMI (ρ = 0.61 to -0.69).
• High predictive performance for estimating PMIs ≥ 7-60 days (AUCs: 0.904-0.984).
• Brain area ratio showed highest accuracy for PMIs ≥ 60 days (AUC = 0.984).
• Undetermined causes of death increased significantly with decomposition stage (Stage IV: 92.9%).
• Brain deformation ratio correlated positively with seasonal effects (p = 0.0017).

Conclusions:

• PMCT-based brain decomposition assessment provides objective markers for estimating late PMIs.
• This approach can assist in evaluating the likelihood of cause-of-death in decomposed bodies.
• PMCT offers a valuable tool for forensic analysis of decomposition changes.