Department of Physical Anthropology, Institute of Forensic Medicine, University of Bern, Murtenstrasse 24-28, 3008, Bern, Switzerland.
Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Bern, Bern, Switzerland.
Int J Legal Med. 2023 Nov;137(6):1839-1852. doi: 10.1007/s00414-023-03034-w. Epub 2023 Jun 19.
Computed tomography (CT) scans are a convenient means to study 3D reconstructions of bones. However, errors associated with the different nature of the observation, e.g. visual and tactile (on dry bone) versus visual only (on a screen) have not been thoroughly investigated.
We quantified the errors between modalities for sex estimation protocols of nonmetric (categorical and ordinal) and metric data, using 200 dry pelves of archaeological origin and the CT reconstructions of the same bones. In addition, we 3D surface scanned a subsample of 39 pelves to compare observations with dry bone and CT data. We did not focus on the sex estimation accuracy but solely on the consistency of the scoring, hence, the interchangeability of the modalities.
Metric data yielded the most consistent results. Among the nonmetric protocols, ordinal data performed better than categorical data. We applied a slightly modified description for the trait with the highest errors and grouped the traits according to consistency and availability in good, intermediate, and poor.
The investigated modalities were interchangeable as long as the trait definition was not arbitrary. Dry bone (gold standard) performed well, and CT and 3D surface scans performed better. We recommend researchers test their affinity for using virtual modalities. Future studies could use our consistency analysis and combine the best traits, validating their accuracy on various modalities.
计算机断层扫描（CT）是研究骨骼 3D 重建的一种便捷手段。然而，与观察方式不同相关的误差，例如视觉和触觉（在干骨上）与仅视觉（在屏幕上）之间的误差尚未得到彻底研究。
我们使用 200 具来自考古学的干骨盆和相同骨骼的 CT 重建，量化了性别估计协议中非度量（分类和顺序）和度量数据的模式之间的误差。此外，我们对 39 具骨盆的子样本进行了 3D 表面扫描，以比较与干骨和 CT 数据的观察结果。我们没有专注于性别估计的准确性，而只是关注评分的一致性，因此，模式的可互换性。
度量数据产生了最一致的结果。在非度量协议中，顺序数据的表现优于分类数据。我们对具有最高误差的特征应用了略微修改的描述，并根据一致性和可用性将特征分为好、中、差。
只要特征定义不是任意的，所研究的模式是可互换的。干骨（金标准）表现良好，CT 和 3D 表面扫描表现更好。我们建议研究人员测试他们对使用虚拟模式的亲和力。未来的研究可以使用我们的一致性分析，并结合最佳特征，在各种模式上验证其准确性。
