Estimation of time of death using brain parenchyma attenuation in post mortem computed tomography of brain – In malaysian setting

Abstract

• Brain is first organ to undergo decomposition after death occurs and can be used to estimate early PMI. • Overall average attenuation of brain show linear positive correlation with early PMI. • Attenuation measurement at centrum semiovale, high convexity and parietal lobe can be grouped together and its average attenuation shows good correlation with early PMI. • In regards to one area of brain attenuation that corresponds best to PMI is at high convexity level. To measure brain attenuation of Post Mortem Computed Tomography (PMCT) of brain and to determine the correlation between the Post-Mortem Interval (PMI) and brain parenchymal attenuation value. This was a retrospective cross sectional study conducted at Institut Perubatan Forensik Negara (IPFN) of Hospital Kuala Lumpur from April 2019 to April 2020. Total of 160 PMCT brain samples that met inclusion criteria were examined. A measurement cursor with fixed size was used to measure the brain parenchymal attenuation in Hounsfield Unit (HU). The values were then averaged and plotted against the PMI to assess the correlation. Each brain location average attenuation as well as average attenuation of grouped locations were plotted against PMI to examine if any particular site of the brain had almost similar correlation or trend as the overall attenuation. There was positive linear correlation between the brain parenchymal attenuation changes and PMI, where there was progressive increase in HU values within the time limit of PMCT at our center, in which the longest stood at 31 hours. The best-fit model for the correlation involved the average attenuation of Centrum Semiovale-High Convexity-Parietal (CSHCP) levels. There was positive linear correlation between PMI and brain parenchymal attenuation and within the CSHCP levels, High Convexity was the single location that was most representative of this group, hence can be used to estimate PMI of a brain particularly in early decomposition state.