Early Postmortem Changes in Pancreas: An Antemortem and Postmortem Computed Tomography Study

BACKGROUND: We aimed to investigate early postmortem changes of the healthy pancreas longitudinally across antemortem computed tomography (AMCT) to postmortem computed tomography (PMCT). MATERIALS AND METHODS: This study included adult patients who were treated and died at a university hospital and underwent unenhanced AMCT within seven months before death, and PMCT within 24 hours after death. Included subjects had undergone pathological autopsy between 2013 and 2020 and were proven to have a healthy pancreas on autopsy. The pancreatic parenchyma on images was segmented using CT-value threshold-assisted initial contouring followed by manual slice-by-slice refinement. Their volume, density, and histogram-based distribution parameters (skewness and kurtosis) of the voxel-wise pancreatic density distribution within the segmented pancreas region of interest were measured using an image analyzer on unenhanced AMCT and PMCT. The values were compared statistically. RESULTS: A total of 38 participants were included in the study (male/female, 23/15; mean age, 64.1±15.1 (SD) years). The pancreatic density on AMCT (31.2 ± 8.7 HU) decreased significantly on PMCT (26.6 ± 8.1 HU). Similarly, the pancreatic volume on AMCT (63.8 ± 23.2 ml) significantly reduced on PMCT (56.8 ± 22.6 ml). Histogram skewness of the voxel-wise pancreatic density distribution significantly increased from AMCT to PMCT, whereas histogram kurtosis of this density distribution exhibited a non-significant difference. CONCLUSION: Pancreatic density and volume significantly decrease in early postmortem. These findings provide a basis for interpreting normal postmortem pancreatic imaging.