Factors affecting measurement accuracy in 3D imagery captured using LiDAR: applications for the postmortem setting

Photography is routine in the postmortem setting to document findings and spatial relationships. 3D photography is becoming more available with recent technological advancements, with LiDAR technology being highly accessible. This study used a surrogate to explore the accuracy in using LiDAR in small-medium line measurement (30 mm) on a flat surface in different simulated autopsy/postmortem environments. It showed the accuracy is dependent on surface reflectivity, angle of laser incidence, background environment, and orientation of measurement with an average difference of 1.9 mm. This study demonstrated that already a commercially available LiDAR technology is promising in the postmortem environment. Future studies evaluating irregular surfaces, use of organ tissue, alternative devices, as well as inter- and intra-operator reproducibility would further establish the utility of this technology in forensic pathology practice.