Morphometric Comparison of Clavicle Outlines from 3D Bone Scans and 2D Chest Radiographs: A Shortlisting Tool to Assist Radiographic Identification of Human Skeletons

Abstract

This paper describes a computerized clavicle identification system primarily designed to resolve the identities of unaccounted-for U.S. soldiers who fought in the Korean War. Elliptical Fourier analysis is used to quantify the clavicle outline shape from skeletons and postero-anterior antemortem chest radiographs to rank individuals in terms of metric distance. Similar to leading fingerprint identification systems, shortlists of the top matching candidates are extracted for subsequent human visual assessment. Two independent tests of the computerized system using 17 field-recovered skeletons and 409 chest radiographs demonstrate that true-positive matches are captured within the top 5% of the sample 75% of the time. These results are outstanding given the eroded state of some field-recovered skeletons and the faintness of the 1950's photofluorographs. These methods enhance the capability to resolve several hundred cold cases for which little circumstantial information exists and current DNA and dental record technologies cannot be applied.

A Large‐Sample Test of a Semi‐Automated Clavicle Search Engine to Assist Skeletal Identification by Radiograph Comparison

“…Positive predictive values in serial shortlists for the clavicle matching program compared between the current study (black line; n am = 7361; n pm = 30; n A = 4) and Stephan et al (light gray line; n am = 409; n pm = 17; n A = 2). The bold vertical line highlights shortlist performance when comprised of 10% of the total sample.…”

“…Three charts of serial PPVs were generated: (i) PPVs for each of the four analysts and the overall mean for this study (Fig. ); (ii) the mean for this study ( n am = 7361; n pm = 30; n A = 4) compared to the mean performance observed by Stephan et al ( n am = 409; n pm = 17; n A = 2; Fig. ); and (iii) the mean performance of analysts and skeletal remains common between the two studies, that is, this study ( n am = 7361; n pm = 17; n A = 2), and that of Stephan et al ( n am = 409; n pm = 17; n A = 2; Fig.…”

“…The preservation state of these remains varied from very good to relatively poor. See Table for more information and for illustrative examples. Shadowgrams of the claviculae were generated following the methods described by Stephan et al , and each of the four analysts in this study independently cropped the (same) postmortem shadowgrams.…”

“…See Table for more information and for illustrative examples. Shadowgrams of the claviculae were generated following the methods described by Stephan et al , and each of the four analysts in this study independently cropped the (same) postmortem shadowgrams. Elliptical Fourier descriptors for 40 harmonics were then calculated for each of these shadowgrams (EFA pm ).…”

Standoff human identification using body shape

“…Human body measurements have been used in the field of anthropology for inferring age and gender from skeletal remains [1][2], for inferring genetic population membership [3][4] and for individual identification in forensic anthropology [5]. More recently, body shape has been investigated as a biometric identifier.…”