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Establishing Standards for Side-by-Side Radiographic Comparisons
Abstract
The objectives of this research were to evaluate the use of various anatomical features that are visible in standard radiographs and to develop a standard system of assessing concordant features for making positive identifications through radiographic comparison.The radiographs used in the study include craniofacial (n = 41), chest (n = 100), and proximal femur (n = 49), which were made available by the North Carolina Office of the Chief Medical Examiner. Radiographs were scored for number of concordant features and were analyzed using classification decision trees. The accuracy of the classification tree models was evaluated using a receiver operating characteristic.Two or more points of concordance are required in lateral cranial radiographs for a 97% probability of a positive identification. If more than 1 concordant feature exists on the cervical vertebrae, there is a 99% probability of correct identification. For thoracic and lumbar vertebrae, 4 or more concordant features are required for a 98% probability of correct identification. If there are 1 or more femoral head and neck concordant features, the probability of a correct identification is 94% and 97%, respectively. This study established the minimum number of concordant areas needed to confirm positive identifications in 3 standard radiographic views.
... When antemortem (AM) reference radiographs exist for persons suspected to be part of a mass fatality incident, postmortem (PM) radiographs can be taken and compared with the relevant AM images to assist identification [1][2][3][4][5][6]. Such radiographic comparisons extend beyond forensic odontological examinations of the teeth or dental restorations [7][8][9] to include the natural shape and form of the skeleton [10][11][12]. ...
... Such radiographic comparisons extend beyond forensic odontological examinations of the teeth or dental restorations [7][8][9] to include the natural shape and form of the skeleton [10][11][12]. Concordant skeletal anatomy, between the AM/PM imaging sessions, is indicative of decedent identity, while discordant skeletal morphology is grounds for an exclusion [5,11,13]. It is especially important to note that exclusions can be of equal value to concordances, especially where the identification universe (subset of plausible possible matches from the population at large [14,15]) is small and closed. ...
... Radiographic comparisons can be made for any body region and a wide variety of examples have been previously published: for example, see for skull [38], vertebrae [13,30], pelvis [39], clavicles [32][33][34], hands [11,16,25], knees [26,40], and feet [27]. A major attribute that contributes to the utility of the method for identification, is the high frequency with which diagnostic radiographs are taken during life for medical purposes [5]. These features make radiographic comparison highly relevant to disaster victim identification [1,3,4,29] in both civilian [5,28,41] and military contexts [32,42,43]. ...
Standard plain film medical radiographs often form a valuable line of evidence to identify individuals in large‐scale fatality events. While commonly available, chest radiographs present a challenge that their analysis is somewhat more involved and complex than radiographic records of other body regions. For example, chest radiographs concern subtler morphological varieties of smaller anatomical features across a larger number of skeletal elements in contrast to frontal sinus comparisons that concern a large, (often) single, highly variable void within one bone. This does not detract from or discount chest radiographs as useful identification aids, but it does demand additional prerequisite skills in radiographic interpretation to ensure valid conclusions are attained. When subjects deviate from standardized antemortem (AM) radiographic positions and/or the image quality decreases, the complexity of a chest radiograph comparison is elevated. Generally, the current body of forensic radiographic comparison literature infrequently addresses these more complex circumstances. In this paper, we use real‐world radiographic comparison reference images from a military DVI repatriation context to illustrate these factors and outline some procedures that enable these complexities to be easily recognized and appropriately addressed at case examination. A report for an exemplar case that concurrently highlights multiple factors is presented. For novices learning radiographic comparison methods, this case review saliently demonstrates: (1) why the AM reference radiograph(s) drive(s) the radiographic comparison procedure; (2) why care should be taken for correct positioning of the cervicothoracic junction in postmortem radiography of chest elements.
... According to the information available and the level of confidence, three types of identification are used. Tentative, when the possible identity is based on circumstantial evidence, such as personal belongings [1]. Presumptive, when evidence indicate an identity without exclusions, but they meet a lesser standard than positive [1,2]. ...
... Tentative, when the possible identity is based on circumstantial evidence, such as personal belongings [1]. Presumptive, when evidence indicate an identity without exclusions, but they meet a lesser standard than positive [1,2]. Positive identification relies on a higher level of probability and on a set of features that is shared between Postmortem (PM) and Antemortem (AM) evidence. ...
... Positive identification relies on a higher level of probability and on a set of features that is shared between Postmortem (PM) and Antemortem (AM) evidence. The experts should determine the uniqueness of the feature considered in the comparison [1,2], and more importantly, establish the probability that an individual present a set of traits [3]. The main weakness in forensic anthropological identification is the traditional subjective nature of the comparisons which has been criticized time after time, especially for the lack of quantitative evidence that would prove an identification [4]. ...
The human skeleton displays an immense array of traits and variant features that are elements of inter-individual variability. The general assumption is that they may represent individualizing markers for the personal identification of unidentified decedents, but very few works consider them as such. This review provides an overview on the possible use of non-metric traits and skeletal variants for personal identification. The paper discusses the issues related to unquantified comparisons, then it presents a statistical approach based on frequencies of these features for identifying unknown remains. Narrowing down an initial number of 1000 papers, the core of the review is represented by 10 papers that considered non-metric traits and skeletal variants as individualizing features, according to both qualitative and quantitative assessments. Despite visual examination remains the gold-standard, more sound methods are requested to quantify the strength of a match or a mismatch. This especially applies in the wake of juridical demands, hence also satisfying the desire of prosecutors and judges to rely on a “quantified” risk. To this purpose, non-metric traits and skeletal variants seem to be a suitable tool to provide quantified evidence, when related frequencies are known.
... Even though they are a direct result of cardiovascular disease (circulatory disease), they are usually "ignored", either because the calcified plaques are not in situ or mainly because they have not been adequately studied [6]. The likelihood of identifying an individual from the analysis of skeletal lesions increases considerably when there are medical records and, more specifically, when imaging assessments are performed during the lifetime (preferably not long before death) since these can be replicated and superimposed, allowing the confirmation or rejection of a presumed identity [7,8]. Atherosclerosis confers an identical potential for identification, but only as a complementary method following standardized individualization procedures. ...
Atherosclerosis is an inflammatory disease that, in its more developed stages, can lead to the calcification of fatty plaques on the walls of arteries, resulting in the appearance of new bone elements. It is a condition that has been studied and documented little in the context of paleopathology, especially in the framework of forensic anthropology. This article analyzed the skeletal remains of 71 individuals (35 females and 36 males) from the Luís Lopes Identified Collection of the National Museum of Natural History and Science in Lisbon, 31 of whom had an autopsy report. An attempt was made to ascertain whether these bone elements resulting from atherosclerotic calcification would resist cadaveric decomposition and whether they would be recoverable several years after burial, and a survey was carried out of their distribution according to sex and age, as well as their association with other pathologies, such as osteoporosis and cardiac and renal pathologies. An imaging analysis of an atherosclerotic plaque was also carried out to complement the macroscopic analysis and present other methods of identifying plaques. It was concluded that each atherosclerotic calcification has a unique profile, which can be useful for identification, especially in cases where the individual shows a severe condition. In terms of identification potential, the analysis of calcified atherosclerotic plaques can be useful, as they can corroborate or reject an identification. However, it always requires the existence of ante-mortem imaging exams and must always be used in addition to other identification methods. Regardless of the identification, these plaques are bone elements resulting from a pathology and should, therefore, be known and recognized by the scientific community.
... Their objective was to establish the time between The sample was divided into no DISH (only score 0), early DISH (score 3, plus an additional score of 2 or 3 and a score of 1 or 2; or 3 adjacent scores of 2), and definite DISH (as defined by Resnick and Niwayama [31] It is possible for DISH to be captured through radiographs during medical visits, often for unrelated reasons. An estimated 40% of clinical radiographs include the thoracic region of the spine [47]. Therefore, if antemortem records are available, DISH has the potential to be assessed in an estimated 40% of clinical radiographs that also enable antemortem-postmortem radiographic comparisons. ...
The use of skeletal pathologies in establishing positive identifications via radiographic comparison is often avoided—and thus understudied—due to the dynamic nature of the skeleton in response to pathological conditions. Using an online survey, this study tests the accuracy of diffuse idiopathic skeletal hyperostosis (DISH), a relatively common vertebral pathology, in making positive identifications through radiographic comparison. Three digital radiographic images from 51 DISH-positive individuals were obtained from the Boston Medical Center: one image taken at a baseline date (Group A), one image taken within 2 years from baseline (Group B), and one image taken greater than 4.5 years from baseline (Group C). Survey participants were tasked with comparing between simulated lateral “antemortem” and “postmortem” images from living patients and identifying which pair represented the same individual at different time intervals. A total of 40 responses were recorded and analyzed by measuring accuracies, sensitivities, and specificities. Information about survey participants’ field, degree, experience working with radiographs, and familiarity with DISH was also recorded. Series 1 compared Group A to Group B images and resulted in an accuracy of 87.3%, sensitivity of 46.9%, and specificity of 94.3%. Series 2 compared Group A to Group C images and resulted in an accuracy of 83.4%, sensitivity of 34.3%, and specificity of 95.8%. The results indicate that the progressive changes associated with DISH render the condition unreliable for making positive identifications but suggest that DISH could be used to winnow potential matches.
... Recognition by forensic anthropologists of the need for standardized, validated methods for identification predates the NAS report (4)(5)(6), as does much of the research aimed at validation of anthropological methods of identification. Anthropologists have continued to contribute to this discussion since the NAS report was published (7)(8)(9)(10)(11). ...
Forensic identification of human remains has long been a core contribution of forensic anthropologists to death investigations. The array and scientific robusticity of the identification methods employed by the anthropologist has evolved in the last several decades, and as with other nonidentification methods, anthropologists have embraced the progression toward the use of validated and statistically defensible methods for identification. This article presents an overview of the role that the forensic anthropologist plays in the identification of human remains and the evolution of anthropological methods of identification.
Introduction
Comparative radiography is a forensic identification and shortlisting technique based on the comparison of skeletal structures in ante-mortem and post-mortem images. The images (e.g., 2D radiographs or 3D computed tomographies) are manually superimposed and visually compared by a forensic practitioner. It requires a significant amount of time per comparison, limiting its utility in large comparison scenarios.
Methods
We propose and validate a novel framework for automating the shortlisting of candidates using artificial intelligence. It is composed of (1) a segmentation method to delimit skeletal structures’ silhouettes in radiographs, (2) a superposition method to generate the best simulated “radiographs” from 3D images according to the segmented radiographs, and (3) a decision-making method for shortlisting all candidates ranked according to a similarity metric.
Material
The dataset is composed of 180 computed tomographies and 180 radiographs where the frontal sinuses are visible. Frontal sinuses are the skeletal structure analyzed due to their high individualization capability.
Results
Firstly, we validate two deep learning-based techniques for segmenting the frontal sinuses in radiographs, obtaining high-quality results. Secondly, we study the framework’s shortlisting capability using both automatic segmentations and superimpositions. The obtained superimpositions, based only on the superimposition metric, allowed us to filter out 40% of the possible candidates in a completely automatic manner. Thirdly, we perform a reliability study by comparing 180 radiographs against 180 computed tomographies using manual segmentations. The results allowed us to filter out 73% of the possible candidates. Furthermore, the results are robust to inter- and intra-expert-related errors.
When human remains are examined, three questions always need to be answered: who is the deceased, what was the cause of death, and when did the death occur, the former question being the most relevant. The identification of half or fully skeletonized human remains is a complex process and always requires the use of methods that allow individualization beyond any reasonable doubt. However, no matter how vigorous the search for identification, this is not always achieved. Here, the author presents two cases in which identification was exhaustively attempted but not achieved despite the existence of an osteo implanted device in one case and the presence of documents in the other. In one case, we could not find a potential identity for the deceased, while in the other we found a possible identity but not a family member to provide antemortem data to confirm it. Although the scientific literature tends to favour the publication of cases with favourable outcomes, one should also learn from failures, which is the reason why the author decided to publish his unsuccessful experiences. The reasons for the failures are discussed, as well as methodological improvements for future cases.
In this study, we explore how image resolution and tissue shielding can impact correct classification rates (CCRs) of infracranial radiographic comparisons undertaken using small field-of-view radiographs. Thirty-six identification arrays (using clavicles and seventh cervical vertebra) were constructed with each array comprised of five radiographs: one X-ray of a single dry bone (postmortem [PM] skeletal image) and four simulated antemortem [AM] radiographs (radiographs taken pre-skeletization). One AM radiograph in each array represented the ground truth match to the PM radiograph (=25% rate of randomly selecting the correct match). Radiographs were digitally manipulated, so that four varieties of decreasing blur (Gaussian blur = 12–0 pr across 24 arrays), and, for PM clavicles, four varieties of decreasing hard tissue shielding (opacity of 40–0% across 12 arrays) existed. Arrays were evaluated, for their correct PM/AM pair, by 8 anthropologists trained in chest radiograph comparison (CXR; either currently or formerly competency certified by the Defense POW/MIA Accounting Agency CXR training program), 28 current American Board of Forensic Anthropology (ABFA) diplomates and 30 novices. Analysts’ CCRs substantially improved when Gaussian blur was <10 pr (55% CCR at >10 pr vs. 89% for <10 pr). Tissue shielding effects increased CCRs on average by +10% for each −10% opacity step (between 40–0% opacity). The CXR anthropologists were the most tolerant of the more challenging identification contexts (highest blur and opacity), reconfirming that analyst training and expertise is an important factor, especially when poorer quality radiographic images are the subject of analysis.
Radiographic comparison for identification is widely utilized. However, these methods are qualitative and subject to analyst ability to correctly read and interpret radiographs. With regards to infra‐cranial radiographs, few studies have been conducted to explore the role of practitioner expertize on correct classification rates (CCRs). Here, we undertake two such studies using forensic anthropologists [American Board of Forensic Anthropology (ABFA) certified, practicing but not board‐certified anthropologists, and chest radiograph comparison (CXR) anthropologists trained via the Defense POW/MIA Accounting Agency CXR competency training program] and compare their results to novices. To ensure participants only referred to the same skeletal morphology, we cropped radiographs to single bones. An array of four simulated antemortem radiographs was presented to each assessor with each postmortem radiograph. Assessors evaluated arrays for a correct match, which was always present, yielding a 25% rate for random correct selections. Study 1 used anteroposterior C7, posteroanterior second metacarpal, and lateral calcaneus radiographs (three arrays each for nine arrays total), which yielded 86, 81, 69, and 68% mean CCRs for CXR experts, ABFA anthropologists, non‐ABFA anthropologists and novices, respectively. Study 2 used anteroposterior C7 and left clavicles (three arrays each for six arrays total), yielding mean CCRs of 100, 96, and 84% for CXR experts, ABFA anthropologists and novices, respectively. As reflected by the CCRs, expertise is clearly a factor for radiographic comparisons, evident not just between novices and anthropologists, but also between anthropologists. We recommend all radiographic comparison analysts be subject to competency/proficiency tests prior to their engagement for forensic casework.
INTRODUCTION: Comparative radiography is a forensic identification technique based on the comparison of skeletal structures in ante-mortem and post-mortem radiographic data to determine the identity of a deceased person. Several works have tackled its automation using different approaches but all of them require the manual segmentation of the skeletal structure’s silhouette.
MATERIALS AND METHODS: The radiograph segmentation task has been automated using convolutional neural networks. We have developed a deep network able to accurately segment the skeletal structure of interest within a radiograph. It requires only 200 labelled radiographs to be trained, and has been applied to two problems: (1) the segmentation of clavicles in chest radiographs using the JSRT dataset; and (2) the segmentation of frontal sinuses in head radiographs provided by the Hospital de Castilla-La Mancha (Spain).
RESULTS AND DISCUSSION: We achieve human-competitive performance in the segmentation of clavicles in chest radiographs (average Dice Similarity Coefficient 0.939) and high-quality segmentation results in the segmentation of frontal sinuses in head radiographs (0.823). The automatic segmentations of frontal sinuses obtain similar results to manual ones for the decision-making task. Specifically, both manual and automatic segmentation allows 50% of the sample to be filtered. In fact, the positive match is always located among the best first 5 matches provided by our system.
CONCLUSIONS: This automatic segmentation framework comprises a first step towards a computer-aided decision support system in comparative radiography, where the resulting segmentation is employed in an image registration pipeline as part of the decision-making process.
The recognition and diagnosis of pathological conditions can provide identifying characteristics that lead to the identification of unknown remains. While pathological lesions on dry bone are usually detected by gross visual examination, potentially individuating lesions may not be detected without radiographic analysis. Radiography may be especially important to diagnose metastatic cancer, where lesions may begin on the inner surface of the bone. The objective of this study was to determine if and on what skeletal elements metastatic cancerous lesions are detected more frequently when using radiographs compared to dry bone examination. Multiple skeletal elements from 30 individuals with reported soft tissue cancers were examined for the presence of visible lesions on dry bone and on radiographs. Results show that 63% of the sample with reported soft tissue cancers exhibited visible lesions. Of these, 42% of the lesions were identified solely on radiographs and 58% exhibited distinct lesions using both dry bone and radiographic analyses. A comparison of the two methods of lesion detection indicates that macroscopic analysis alone cannot capture the range of cancerous lesion manifestations. Here, I suggest a method for practitioners that minimizes time and expense in radiographing to prioritize skeletal elements that best exhibit cancerous lesions that would have otherwise been hidden on dry bone.
In this position statement, the Board members of the Forensic Anthropology Society of Europe (FASE) argue that forensic anthropology methods can be used as means of personal identification, particularly in situations with limited availability of traditional identification methods (i.e. dactyloscopy, odontology, and molecular genetic analysis). This statement has been issued taking into account the international migration crises related to thousands of deaths worldwide, in which the utility of these traditional means of identification has been sporadic to non-existent. The statement is however not limited to deaths related to the migration crises, as similar problems may occur in fatalities en masse such as in natural disasters and armed conflicts, and on a smaller scale in cases of homeless or otherwise socioeconomically disadvantaged persons. The number of reports on personal identification based on sound anthropological methodology is increasing in the scientific literature. However, more research is needed to develop evidence-based standard operating procedures and statistical frameworks. It remains essential to raise awareness among forensic practitioners, law enforcement, and judiciary professionals on the utility of forensic anthropology in cases where it can provide sufficient information for identification.
Objective
We aimed to evaluate whether the internal structures of the human ear have anatomical characteristics that are sufficiently distinctive to contribute to human identification and use in a forensic context.
Materials and methods
After data anonymisation, a dataset containing temporal bone CT scans of 100 subjects was processed by a radiologist who was not involved in the study. Four reference images were selected for each subject. Of the original sample, 10 examinations were used for visual comparison, case by case, against the dataset of 100 patients. This visual assessment was performed independently by four observers, who evaluated the anatomical agreement using a Likert scale (1–5). Inter-observer agreement, true positive rate, positive predictive value, true negative rate, negative predictive value, false positive rate, false negative rate and positive likelihood ratio (LR+) were evaluated.
Results
Inter-observer agreement obtained an overall Cohen’s Kappa = 99.59%. True positive rate, positive predictive value, true negative rate and negative predictive value were all 100%.
Conclusion
Visual assessment of the mastoid examinations was shown to be a robust and reliable approach to identify unique osseous features and contribute to human identification. The statistical analysis indicates that regardless of the examiner’s background and training, the approach has a high degree of accuracy.
Personal identification represents one of the most crucial activities of forensic pathologists, odontologists, radiologists and/or anthropologists. It is also one of the least standardised procedures, as it takes into consideration, case by case, the comparison between different anatomical and acquired features that require critical judgment by an expert operator.
This article is about identification of cadavers and human remains, focusing mainly on the more accepted methods to establish identity. Emphasis is provided on the methods applied to bodies in an advanced state of decomposition and/or skeletonized and the contribution of each sub-discipline in the field of identification, including anthropology, odontology, genetics, imagiology and dactiloscopy. Some insights on the history of personal identification and emerging issues and future perspectives are discussed, such as the need of implementation of best practices to identification and the comparative phase of identification. To do this, is of paramount importance that all the countries adopt a same policy to collect ante and post mortem data, which has been claimed by all international agencies dealing with this subject.
This manuscript describes the use of comparative radiography of the chest to facilitate positive identification of human remains in advanced stages of decomposition. The method reported by Stephan et al. for positive identification of dry, disarticulated skeletal elements was used on semifleshed, decomposing remains. Positive identification was established through multiple points of concordance observed in radiographs of the left and right clavicles and the C5-T1 vertebrae. This case study demonstrates the applicability of the Stephan et al.'s method in cases involving decomposing remains.
Many methods have been used to identify unknown persons. The most common is the study of fingerprints, which is one of the few methods in which data can be stored and retrieved in a precise and cost-effective manner.
The asymmetry of the frontal sinuses has stimulated several attempts to identify persons by analyzing measurements of the sinuses obtained from plain x-ray films. However, an objective and reproducible method has not been achieved.
The objective of this paper is to report on a method of making standardized measurements of the frontal sinuses on radiographs and storing the resultant information in a computer databank. To test the system, the author made new measurements on 100 x-rays and entered the results into a computer databank that contained information on earlier measurements of the same 100 x-rays and on 400 others. With the aid of the databank, the author was able to rapidly and accurately match each new measurement with the earlier measurement. The author concludes that such a system is a simple and cost-effective method of establishing the identification of unknown persons for whom frontal sinus x-rays exist.
The receiver operating characteristic (ROC) curve, which is defined as a plot of test sensitivity as they coordinate versus its 1-specificity or false positive rate (FPR) as the x coordinate, is an effective method of evaluating the performance of diagnostic tests. The purpose of this article is to provide a nonmathematical introduction to ROC analysis. Important concepts involved in the correct use and interpretation of this analysis, such as smooth and empirical ROC curves, parametric and nonparametric methods, the area under the ROC curve and its 95% confidence interval, the sensitivity at a particular FPR, and the use of a partial area under the ROC curve are discussed. Various considerations concerning the collection of data in radiological ROC studies are briefly discussed. An introduction to the software frequently used for performing ROC analyses is also presented.
Non-contrast-enhanced computed tomography (CT) is the primary imaging method in craniofacial trauma. Other imaging modalities (contrast enhanced CT, magnetic resonance imaging, conventional x-rays) might be used to complement primary imaging or address specific complications after trauma. This chapter summarizes technical background, recent developments and applications of the different radiologic modalities. The second part focuses on radiological assessment of trauma and suggests a practical approach to structured reading of CT in craniofacial trauma.
Tim White and Pieter Folkens, the team behind the bestselling text, Human Osteology, Second Edition, have created the ideal concise guide for professional anthropologists, osteologists, law enforcement officers, and forensic specialists working with human bones in the field or laboratory. In addition to essential text information, hundreds of photographs are included, showing a maximum amount of anatomical information and providing a valuable tool in comparing specimens for rapid identification across the broad landscapes of law enforcement, forensics, anatomy, archaeology, and paleontology. Book jacket.
Tim White and Pieter Folkens, the team behind the bestselling text, Human Osteology, Second Edition, have created the ideal concise guide for professional anthropologists, osteologists, law enforcement officers, and forensic specialists working with human bones in the field or laboratory. In addition to essential text information, hundreds of photographs are included, showing a maximum amount of anatomical information and providing a valuable tool in comparing specimens for rapid identification across the broad landscapes of law enforcement, forensics, anatomy, archaeology, and paleontology. Book jacket.
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.
This case study demonstrates the importance of involving an anthropologist in forensic situations with decomposed remains. Anthropological consultation was used in conjunction with the comparison of antemortem and postmortem radiographs to establish positive identification of unknown, decomposed remains. The remains had no traditional identifying features such as fingerprints or dental. Through anthropological analysis, it was determined the decedent was male, between 20 and 23 years at time of death and c. 5′2″ tall. This information allowed for a presumptive identification and a request for antemortem radiographs. The missing person was identified comparing the spinous processes of the cervical and thoracic vertebrae between ante- and postmortem radiographs.
Personal identification of unidentified bodies is crucial for ethical, juridical and civil reasons and is performed through comparison between biological data obtained from the cadaver and antemortem material from one or more missing persons to whom the body may have belonged in life. The increasing applications of forensic radiology and the wide use of conventional radiography and computed tomography (CT) in routine clinical practice demonstrate the potential of these technologies as tools for verifying the correspondence between an unidentified body and an identity suspect. This paper reviews the literature concerning the application of forensic radiology to the difficult issue of personal identification. Despite the increasing importance of the comparison between radiographic and CT findings, numerous limitations still need to be overcome, including the fact that few forensic centres have access to sophisticated X-ray technologies and that the reliability of those technologies for detecting specific morphological traits and bone lesions is a matter of intense debate. In addition, as with other morphological methods for identification, comparisons between antemortem and postmortem data require standardisation and statistical analysis, especially in Europe where there are very few indications concerning the admission in court of evidence obtained by anthropological and radiological methods. In the future, with developments in radiographic technologies and increasing numbers of studies on their application to the forensic setting, radiology will become one of the most useful tools in the field of personal identification.
This study investigated the value of antemortem (AM) and postmortem (PM) radiographs of the claviculae and C3-T4 vertebrae to identify skeletons of missing U.S. soldiers from past military operations. In total, 12 field-recovered skeletons and AM chest radiographs of 1460 individuals were used. For each skeleton, examiners analyzed an array of AM chest radiographs (up to 1000 individuals) and attempted to identify the correct PM/AM radiographic match. When examiners were able to compare all images within a single test, only true-positive identifications were made. When AM radiographs were presented one-at-a-time, in sequential order, and without examiners having knowledge of array size, erroneous identifications resulted but they were almost exclusively made by untrained examiners (accuracy = 35% vs. 90% for trained examiners). This study demonstrates the value of chest radiographs for the identification of disarticulated and even eroded skeletons, but only when methods are wielded by trained examiners.
Radiography has long been used by anthropologists to establish positive personal identification of human remains in forensic cases. These methods have been largely ad hoc and depend upon specific congenital or pathological bone markers. Court rulings, such as Daubert and Mohan have, however, pushed the discipline toward more statistically supportable methods of identification. This study describes the use of normal morphological variation of the thoracic vertebrae to identify human remains. Radiographs from healthy, male individuals, aged 18-55 were examined to identify normally varying features of vertebral morphology. The frequency of occurrence of these features was calculated, tested, and found to be stable in the given sample. The frequencies were compared to establish which sets of traits varied independently of one another. Finally, unknown radiographs were compared to known samples to test the applicability of this method in determining positive identification, with 21 of 24 (87.5%) unknown radiographs positively identified.
The aims of this study were to verify if frontal sinuses can uniquely identify individuals belonging to family groups using Cameriere methods and to test if kinship can affect the proportion of erroneous identifications. For this purpose, we compared the proportion of false-positive identifications in a sample of 99 individuals within 20 families with a control sample of 98 other individuals without kinship. The results show that the combined use of SOR and the Yoshino code number allows personal identification with a small probability of false positives (p < 10(-6)), even when kinship is taken into account. The present research confirms the importance of studying anthropological frameworks for identification, which leads to reliable methods and allows for both quick and economic procedures.
The article attempts to explain that the dental expert cannot base his identification of an unknown body on the relative frequency of occurrence of any singular dental feature, its particular discrimination potential. Instead, he must make a quantitative and qualitative evaluation of the combination of features involved. The author submits his thoughts on the latter and the guidelines which he, so far, has established for himself.
The identification of unknown human remains by comparison of ante mortem and post mortem radiographs has found wide acceptance in recent years. This report documents two recent cases in Hong Kong in which unequivocal positive identifications were achieved by comparison of radiographs. In both cases, comparison of radiographs was the only available means of establishment of personal identity. The first case involved the identification of a very badly burned body of a 22-year-old male by the matching of the ante mortem and post mortem radiographic images of the cranial base (in particular the sella turcica), hard palate, paranasal air sinuses, mastoid air cells, the lambdoid suture, and the upper molar teeth as revealed on comparable lateral skull films. The second was the identification of a deliberately mutilated torso of a 28-year-old female by comparison of the radiographic images of the lumbar spine, pelvis, and head of the femur as revealed on plain abdominal films taken before and after death. While evidence of injury or surgery did not figure in either of the identifications, the presence of a mild scoliosis and the absence of the twelfth ribs aided identification in the latter case. Emphasis is placed in this account on the value of radiographic comparison as a means of identification because it draws upon the matching of intricate and highly individual patterns of external and internal bony anatomy that are stable over long periods of time. In cases where ante mortem radiographs and photographs are available, establishment of personal identity by comparison of radiographs is deemed preferable to identification by photographic superimposition because radiographic comparison permits the matching of a potentially larger number of unique anatomical features and is less time consuming and technically exacting.
Following mass disasters and individual deaths, dentists with special training and experience in forensic odontology are frequently called upon to assist in the identification of badly mutilated or decomposed bodies. Teeth and dental restorations are resistant to destruction by fire and the elements and are, therefore, useful in identification. The forensic odontologist makes use of dental radiographs taken of the victim before death. These are compared to dental data from the remains to assist in making the identification. Many features of the teeth and numerous characteristics of dental treatment are quite unique. This permits accurate and legally acceptable identification of the remains. The cases described illustrate the procedures and techniques of identification using ante-mortem and post-mortem radiographs.
A comparison of antemortem and postmortem abdominal radiographs showing the lumbar spine was used to establish a positive identification of an unknown cadaver. A positive matching of similar unique skeletal feature, including large osteophytes of the third, fourth, and fifth lumbar vertebrae, distinctive features of the spinous and transverse processes, and identical angulation of an existing right lumbar scoliosis was established. A criticism of the methods used to establish the identification is presented.
Radiographic examination of 42 adult distal left femora and 38 proximal left tibiae revealed that no two bones were identical in the pattern and appearance of the trabeculae. In each case, a minimum of four distinct osseous features was easily visible on radiograph. The results indicate that radiolucencies and radiodensities in the distal femur and proximal tibia are valid individualizing features for establishing a positive personal identification in human remains.
This paper questions the practitioners' deterministic approach(es) in forensic identification and notes the limits of their conclusions in order to encourage a discussion to question current practices. With this end in view, a hypothetical discussion between an expert in dentistry and an enthusiastic member of a jury, eager to understand the scientific principles of evidence interpretation, is presented. This discussion will lead us to regard any argument aiming at identification as probabilistic.
Personal identification of human remains constitutes about 10% of the normal caseload of any forensic medicine practice. Identification can be achieved by a variety of methods, one of which is the comparison of antemortem and postmortem radiographs. There are numerous accounts of cranial and dental radiographic features useful for identification, whereas the availability of postcranial radiographs and especially plates that depict the vertebral column is less widespread among the forensic community. The authors here review the various vertebral features instrumental in positive identification that can be identified on radiographs of the spine.
Comparing skeletal structures between antemortem and postmortem chest radiographs is widely used by forensic specialists from many disciplines to positively identify unknown decedents. However, validity assessments of this method have been fairly limited. This study had three objectives: 1) to quantify the reliability of ante- and postmortem chest radiograph comparison for decedent identification; 2) to identify useful radiologic features supporting decedent identification; and 3) to recognize sources of error in decedent identification related to use of comparative radiographs. A forensic pathologist, a forensic anthropologist, and two radiologists participated in the study. Our results showed that chest radiograph comparisons proved reliable, if basic decedent information was provided, and antemortem and postmortem radiographs were adequately positioned and exposed. A "morphological approach" using normal anatomical structures for comparison may provide the most efficient method for accurate identification.
Forensic odontology plays an important role in the identification of human remains. While numerous studies have proven conclusively the uniqueness of the human dentition, forensic odontologists worldwide remain divided about the need for a minimum number of concordant points to confirm dental identification. This study reviewed 690 cases from the archives of the Forensic Odontology Unit, The University of Adelaide, to determine the validity of using a minimum number of concordant points to positively identify human remains. It was found that positive identification had been established using a varying number of concordant points. Although the incidence of positive identification was more frequent with a minimum of 12 concordant points, there were numerous cases where 12 or more concordant points failed to achieve a positive identification. Identities were also confirmed in some cases using less than 12 points of correspondence. There appears to be no basis for defining a minimum number of concordant points necessary before a positive identification can be made on dental evidence. Rather, the findings of this study reinforce the view that each case has its own individuality and should be treated as such.
Films of the lumbosacral spine of 936 healthy young males were reviewed, utilizing the double-reading technic. The men were Air Force Academy or Air Cadet applicants between the ages of seventeen and twenty-seven. All were in good general health and denied any recent or remote symptoms relating to the lumbosacral spine. Hence, they represent a large series of “healthy” young males with “normal” lumbosacral spines. Anteroposterior and lateral views were obtained, usually in the erect position. Repeat or additional studies were made when indicated. All apparent normal variations, anomalies, and abnormalities were tabulated (Table I). There were also found isolated cases of calcified splenic capsule, possible giant-cell tumor, and old Legg-Perthes disease, but not in sufficient number to warrant tabulation. It is felt that the findings reported in Table I provide a valuable statistical study for reference, teaching, and forensic purposes.
This paper emphasizes the need for objectivity and standardized methodologies in the forensic sciences, particularly physical anthropology. To this end, a review of important events in scientific evidence admissibility law, particularly the standards set in the case of Daubert v. Merrell-Dow Pharmaceuticals, Inc., 1993, is presented. The method of confirming a putative identification by visual comparison of antemortem and postmortem frontal sinus radiographs is examined in light of current admissibility standards. The technique is revealed to have a number of shortcomings, including a lack of empirical testing, no estimates of potential error rates, no standards controlling the technique's operation, and no objective determination standards. These shortcomings may, in some instances, prevent resulting conclusions from being admissible evidence. It is suggested that some methods (including frontal sinus comparison) may require more rigorous testing in order to meet these new and stricter standards.
It is often suggested that the frontal sinus morphology of no two individuals is alike, and that the configuration of the frontal sinus is as unique to an individual as his or her fingerprints. However, no empirical, quantitative testing of the uniqueness of frontal sinus outlines has ever been performed. Such testing is necessary for frontal sinus identifications to be admissible in many courts. This study investigated frontal sinus outline variability using elliptic Fourier analysis (EFA), a geometric morphometric approach that fits a closed curve to an ordered set of data points, generating a set of coefficients that can be used to reproduce the outline. Two-dimensional representations of 808 frontal sinuses (as seen in posterior-anterior cranial radiographs) were digitized, and differences in their shapes were assessed quantitatively by comparing the Euclidean distances between EFA-generated outlines. Results show that Euclidean distances between outlines of different individuals are significantly larger than those between replicates of the same individual, and typicalities show that the probability of finding two different individuals with Euclidean distances less that that between a particular case's replicate is very small. Thus, there is a quantifiable and significant difference between the shapes of individuals' frontal sinus outlines.
The use of frontal sinus radiographs in positive identification has become an increasingly applied and accepted technique among forensic anthropologists, radiologists, and pathologists. From an evidentiary standpoint, however, it is important to know whether frontal sinus radiographs are a reliable method for confirming or rejecting an identification, and standardized methods should be applied when making comparisons. The purpose of the following study is to develop an objective, standardized comparison method, and investigate the reliability of that method. Elliptic Fourier analysis (EFA) was used to assess the variation in 808 outlines of frontal sinuses by calculating likelihood ratios and posterior probabilities from EFA coefficients. Results show that using EFA coefficient comparison to estimate the probability of a correct identification is a reliable technique, and EFA comparison of frontal sinus outlines is recommended when it may be necessary to provide quantitative substantiation for a forensic identification based on these structures.
Many studies have examined the characteristics of the frontal sinuses and their use for forensic purposes, particularly when an individual is edentulous. One of the most widespread classification systems is that proposed by Yoshino et al. The aim of this study was to improve the performance of Yoshino's method for identifying unknown skeletal remains by replacing the first two morphological items, frontal sinus size and bilateral asymmetry, by SOR1 = left frontal sinus area/left orbit area, and SOR2 = right frontal sinus area/right orbit area. According to the bivariate distribution of SOR = (SOR1, SOR2) and available data, we also estimated the probability of positive misclassification.
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