Journal Article

Measuring pelvises in 3D surface scans and in MDCT generated virtual environment: Considerations for applications in the forensic context

Egger, Coraline, Schranz, Sami, Ekizoglu, Oguzhan, Grabherr, Silke, Besse, Marie, Moghaddam, Negahnaz, Campana, Lorenzo, Hoxha, Fatbardha, Abegg, Claudine

2023

Overview

Virtual Anthropology (VA) transposes the traditional methods of physical anthropology to virtual environments using imaging techniques and exploits imaging technologies to devise new methodological protocols. In this research, we investigate whether the measurements used in the Diagnose Sexuelle Probabiliste (DSP) and Ischio-Pubic Index (IPI) differ significantly when 3D models of a bone are generated using 3D surface scans (3DSS) and Multidetector Computed Tomography (MDCT) scans. Thirty pelvises were selected from the SIMON identified skeletal collection. An equal ratio of females to males was sought, as well as a good preservation of the bones. The pelvises were scanned using an MDCT scanner and a 3D surface scanner. The measurements of the DSP and IPI methods on the dry bones (referred to as macroscopic measurements here), and then to the 3D models. The intra- and interobserver, using the Technical Error of Measurement (TEM) and relative Technical Error of Measurement (rTEM) error was assessed, and we aimed to observe if the measurements made on the MDCT and 3DSS generated models were significantly different from those taken on the dry bones. Additionally, the normality of the data was tested (Shapiro-Wilk test) and the differences in measurements was evaluated using parametric (Student t-tests) and non-parametric (Wilcoxon) tests. The TEM and rTEM calculations show high intra and interobserver consistency in general. However, some measurements present insufficient inter- and intraobserver agreement. Student t and Wilcoxon tests indicate potentially significant differences of some measurements between the different environments. The results show that especially in the virtual environment, it is not easy to find the right angle for some of the DSP measurements, However, when comparing the measurement differences between dry and virtual bones, the results show that most of the differences are less than or equal to 2.5 mm. Considering the IPI, the landmarks are already difficult to determine on the dry bone, but they are even more difficult to locate in the virtual environment. Nevertheless, this study shows that quantitative methods may be better suited for application in the virtual environment, but further research using different methods is needed. •Methodologies used in the forensic context need to be proven to be accurate and reliable.•The possibility to re-examine data makes virtual data an important tool in forensic anthropology analysis.•This research compared the measurements taken on pelvises in three different “environments”.•The results show that the DSP measurements seem to be well suited for use in virtual environments.•Conclusions suggest that clearly identifiable landmarks are best suited for application in virtual environments.

• Publisher: Elsevier B.V,Elsevier Limited
• Subject: 3D Surface Scans / Anthropology / Bones / Computed Tomography / Diagnose Sexuelle Probabiliste / Error analysis / Forensic anthropology / Forensic sciences / Human remains / Imaging techniques / Ischio-Pubic Index / Medical imaging / Morphometrics / Pelvis / Scanners / Software / t-test / Three dimensional models / tomography / Virtual Anthropology / Virtual environments