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

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

doi:10.1016/j.forsciint.2023.111813

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

Forensic Sci Int. 2023 Nov:352:111813. doi: 10.1016/j.forsciint.2023.111813. Epub 2023 Sep 1.

Authors

Claudine Abegg¹, Fatbardha Hoxha², Lorenzo Campana¹, Oguzhan Ekizoglu³, Sami Schranz⁴, Coraline Egger⁴, Silke Grabherr⁵, Marie Besse⁶, Negahnaz Moghaddam⁷

Affiliations

¹ Unit of Forensic Imaging and Anthropology, University Centre of Legal Medicine Lausanne-Geneva, Lausanne University Hospital and University of Lausanne, Switzerland.
² Laboratory for Prehistoric Archaeology and Anthropology, Department F.-A. Forel for Environmental and Aquatic Sciences, Faculty of Science, University of Geneva, Switzerland; Unit of Forensic Imaging and Anthropology, University Centre of Legal Medicine Lausanne-Geneva, Geneva University Hospital and University of Geneva, Switzerland.
³ Unit of Forensic Imaging and Anthropology, University Centre of Legal Medicine Lausanne-Geneva, Geneva University Hospital and University of Geneva, Switzerland; Tepecik Training and Research Hospital, Department of Forensic Medicine, Izmir, Turkey.
⁴ Unit of Forensic Imaging and Anthropology, University Centre of Legal Medicine Lausanne-Geneva, Geneva University Hospital and University of Geneva, Switzerland.
⁵ Unit of Forensic Imaging and Anthropology, University Centre of Legal Medicine Lausanne-Geneva, Lausanne University Hospital and University of Lausanne, Switzerland; Unit of Forensic Imaging and Anthropology, University Centre of Legal Medicine Lausanne-Geneva, Geneva University Hospital and University of Geneva, Switzerland.
⁶ Laboratory for Prehistoric Archaeology and Anthropology, Department F.-A. Forel for Environmental and Aquatic Sciences, Faculty of Science, University of Geneva, Switzerland.
⁷ Unit of Forensic Imaging and Anthropology, University Centre of Legal Medicine Lausanne-Geneva, Lausanne University Hospital and University of Lausanne, Switzerland; Swiss Human Institute of Forensic Taphonomy, University Centre of Legal Medicine Lausanne-Geneva, Lausanne University Hospital and University of Lausanne, Switzerland.

PMID: 37742459
DOI: 10.1016/j.forsciint.2023.111813

Abstract

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.

Keywords: 3D Surface Scans; Computed Tomography; Diagnose Sexuelle Probabiliste; Ischio-Pubic Index; Morphometrics; Pelvis; Virtual Anthropology.

MeSH terms

Bone and Bones
Female
Forensic Anthropology / methods
Humans
Imaging, Three-Dimensional*
Male
Multidetector Computed Tomography*
Pubic Bone