A Comparative Analysis of Computed Tomography, Photogrammetry, and Structured Light Scanning for Biological Sex...

Advanced scanning techniques are increasingly used to aid in forensic human identification by enabling rapid and non-destructive documentation of remains, and permitting measurements not possible on dry bone. However, to ensure that the results achieved are reliable, methods must be rigoursly tested and validated. By reviewing relevant literature, this paper compares the use of three popular advanced imaging techniques used to aid forensic human identification - computed tomography (CT), structured light scanning (SLS), and photogrammetry - with a focus on biological sex estimation from 3D rendered models of the cranium, mandible, and pelvis. Each technology was assessed based on its accuracy, speed, cost, portability, level of training, and software requirements in a forensic context. This review highlights that while CT continues to be considered the 'gold standard', structured light scanners and photogrammetry offer significant practical advantages for virtual skeletal analysis. Despite their accuracy and reliability, CT machines are expensive, difficult to transport, and require significant training to operate and utilise relevant software. SLSs can be easy to transport and do not demand significant training to operate, but extensive training is preferable for data interpretation. Further research is required to establish the accuracy of using SLS for sex estimation. Photogrammetry is cost effective, yields a high accuracy, requires minimal training, and the required equipment is easily transported. This paper highlights that both SLS and photogrammetry are viable alternatives to CT for creating accurate models of bones for biological sex estimation. This study intends to act as a guide for forensic anthropologists when selecting which advanced imaging techniques to employ in various forensic contexts.