1.10. Postmortem interval estimation: Value of postmortem cerebral CT

Abstract

Objective After death a series of changes naturally occurs in the human body. Understanding these changes and the contributing factors will lead to a better understanding of the normal process of hypostasis and decomposition, a better estimation of the postmortem interval (PMI) and thus to a better diagnosis of cause and time of death. The aim of this study was to investigate the correlation between the PMI and postmortal intracranial density measurements. Materials and method We retrospectively investigated 61 postmortal cerebral CT scans. We measured the density in Hounsfield units (HU) of the dorsal part of the superior sagittal sinus, vitreous humor left and right and the anterior and posterior horn of lateral ventricles left and right. Correlation between density and PMI was determined using linear regression and is reported using the Pearson׳s correlation coefficient. Results The PMI range was 3.0–45.1h. All densities showed increase over time. This was not significant for the dorsal part of the superior sagittal sinus and vitreous humor (resp. 0.19h per HU; p =0.18; HU 56.1–112.0; Pearson׳s r =0.20 and 0.51h per HU; p=0.12; HU 7.5–29.8; Pearson׳s r =0.23). However, the lateral ventricles showed significant increase of density over time (1.7h per HU; p r =0.65; HU 4.7–18.8). Conclusion The normal postmortal changes are detectable in density of the intracranial structures. This goes especially for the HU increase of liquor during the postmortem interval. This could be of great value for forensic methods to estimate the PMI and needs further prospectively investigation, which we are currently performing.