Disaster victim identification: new applications for postmortem computed tomography

Combining anthropology and imaging to reconstruct antemortem trauma for identification purposes

Identification of unidentified remains involves a comparison of ante- and postmortem features using biological identifiers. Anthropological identifiers, referred to by International Criminal Police Organization (INTERPOL) as secondary identifiers, have often been judged less reliable than DNA, fingerprints and dental records (referred to as primary identifiers). However, anthropological identifiers have been proven as discriminatory as the primary sources in many instances, and play a decisive role in positive identification. To guarantee better use of anthropological identifiers, it is not only essential to develop standard protocols and statistical frameworks, but also to test different identification approaches in cases from daily practice. Evidence of skeletal antemortem trauma can be a valuable aid in the identification process, especially if the exact type of traumatic event causing the injury is identified. Here, we present a case in which the combination of anthropological analysis and imaging confirmed an interesting and unique sequence of antemortem traumatic events in incomplete skeletal remains. The remains were assumed to pertain to an individual who went missing several years earlier, and whose medical records revealed a unique history of trauma to the right femur. The individual had sustained a fracture due to a fall from a high height followed, 10 years after the primary trauma, by a gunshot wound to the same bone; both treated by intramedullary nail fixation. While the anthropological analysis matched the biological profile of the missing individual and identified a healed defect to the right femur compatible with a gunshot wound, the radiological examination indicated that the bone underwent three surgical procedures on different occasions. Radiological examination also identified a pre-existing healed fracture adjacent to the gunshot defect. In addition to presenting the identification process in this specific case, this article discusses the difficulties in antemortem trauma interpretation, importance of combining macroscopic and radiological analysis to aid the reconstruction of previous traumatic events and mechanisms of injury from healed fractures that can play important roles in forensic human identification.

Metric evaluation of the anterior nasal spine to estimate sex and population group in South African individuals

INTRODUCTION

The anterior nasal spine is a pointed, midline projection of the maxilla. This bony structure dictates the overlying soft tissues providing the phenotypic features of the nose and upper lip and determines the differences in the mid-face morphology. Little data is available on the metric features of the Anterior nasal spine (ANS). This study aimed to perform metric evaluations of the ANS of white and black South African males and females to ascertain if morphological variations exist and if the differences are viable for the use in sex and population identification.

MATERIALS AND METHODS

The sample included 100 CBCT images for each population and sex group. Linear and angular measurements of the ANS were recorded in both the sagittal and axial planes.

RESULTS

Classification decision trees (pruned) were fitted to ascertain the relationship between population group, sex and the ANS measurements including and excluding age. For population group, all the ANS measurements were statistically significant for females but in males, all the ANS measurements were significant when performed individually. However, when fitted to the classification tree, Sagittal 2 did not show any statistical significance. When considering sex, only 2 of the ANS measurements (Sagittal 2 and Axial 1) were found to be significant. The results did not differ significantly when comparing the decision trees including and excluding age.

CONCLUSIONS

White South African individuals presented with a longer ANS that produced a more acute angle whereas black South African individuals presented with a shorter ANS and a more obtuse angle. Additionally, males presented with a longer ANS compared to females. ANS measurements were found to be more relevant for population discernment than for sex.

Detecting missing teeth on PMCT using statistical shape modeling

The identification of teeth in 3D medical images can be a first step for victim identification from scant remains, for comparison of ante- and postmortem images or for other forensic investigations. We evaluate the performance of a tooth detection approach on mandibles with missing parts or pathologies based on statistical shape models. The proposed approach relies on a shape model that has been built from the full lower jaw, including the mandible and teeth. The model is fitted to the target, resulting in a reconstruction, in addition to a label map that indicates the presence or absence of teeth. We evaluate the accuracy of the proposed solution on a dataset consisting of 76 target mandibles, all extracted from CT images and exhibiting various cases of missing teeth or other cases, such as roots, implants, first dentition, and gap closure. We show an accuracy of approximately 90% on the front teeth (including incisors and canines in our study) that decreases for the molars due to high false-positive rates at the wisdom teeth level. Despite the drop in performance, the proposed approach can be used to obtain an estimate of the tooth count without wisdom teeth, tooth identification, reconstruction of the existing teeth to automate measurements taken as part of routine forensic procedures, or prediction of the missing teeth shape. In comparison to other approaches, our solution relies solely on shape information. This means it can be applied to cases obtained from either medical images or 3D scans because it does not depend on the imaging modality intensities. Another novelty is that the proposed solution avoids heuristics for the separation of teeth or for fitting individual tooth models. The solution is therefore not target-specific and can be directly applied to detect missing parts in other target organs using a shape model of the new target.

Machine Learning Models for Prediction of Sex Based on Lumbar Vertebral Morphometry

BACKGROUND

Identifying skeletal remains has been and will remain a challenge for forensic experts and forensic anthropologists, especially in disasters with multiple victims or skeletal remains in an advanced stage of decomposition. This study examined the performance of two machine learning (ML) algorithms in predicting the person's sex based only on the morphometry of L1-L5 lumbar vertebrae collected recently from Romanian individuals. The purpose of the present study was to assess whether by using the machine learning (ML) techniques one can obtain a reliable prediction of sex in forensic identification based only on the parameters obtained from the metric analysis of the lumbar spine.

METHOD

This paper built and tuned predictive models with two of the most popular techniques for classification, RF (random forest) and XGB (xgboost). Both series of models used cross-validation and a grid search to find the best combination of hyper-parameters. The best models were selected based on the ROC_AUC (area under curve) metric.

RESULTS

The L1-L5 lumbar vertebrae exhibit sexual dimorphism and can be used as predictors in sex prediction. Out of the eight significant predictors for sex, six were found to be particularly important for the RF model, while only three were determined to be important by the XGB model.

CONCLUSIONS

Even if the data set was small (149 observations), both RF and XGB techniques reliably predicted a person's sex based only on the L1-L5 measurements. This can prove valuable, especially when only skeletal remains are available. With minor adjustments, the presented ML setup can be transformed into an interactive web service, freely accessible to forensic anthropologists, in which, after entering the L1-L5 measurements of a body/cadaver, they can predict the person's sex.

Nucleic Acids Persistence-Benefits and Limitations in Forensic Genetics

The analysis of genetic material may be the only way to identify an unknown person or solve a criminal case. Often, the conditions in which the genetic material was found determine the choice of the analytical method. Hence, it is extremely important to understand the influence of various factors, both external and internal, on genetic material. The review presents information on DNA and RNA persistence, depending on the chemical and physical factors affecting the genetic material integrity. One of the factors taken into account is the time elapsing to genetic material recovery. Temperature can both preserve the genetic material or lead to its rapid degradation. Radiation, aquatic environments, and various types of chemical and physical factors also affect the genetic material quality. The substances used during the forensic process, i.e., for biological trace visualization or maceration, are also discussed. Proper analysis of genetic material degradation can help determine the post-mortem interval (PMI) or time since deposition (TsD), which may play a key role in criminal cases.

Development of individual identification method using thoracic vertebral features as biometric fingerprints

Identification of individuals is performed when a corpse is found after a natural disaster, incident, or accident. DNA and dental records are frequently used as biometric fingerprints; however, identification may be difficult in some cases due to decomposition or damage to the corpse. The present study aimed to develop an individual identification method using thoracic vertebral features as a biological fingerprint. In this method, the shortest diameter in height, width, and depth of the thoracic vertebrae in the postmortem image and a control antemortem were recorded and a database was compiled using this information. The Euclidean distance or the modified Hausdorff distance was calculated as the distance between two points on the three-dimensional feature space of these measurement data. The thoracic vertebrae T1-12 were measured and the pair with the smallest distance was considered to be from the same person. The accuracy of this method for identifying individuals was evaluated by matching images of 82 cases from a total of 702 antemortem images and showed a hit ratio of 100%. Therefore, this method may be used to identify individuals with high accuracy.

Estimation of sex based on metrics of the sternum in a contemporary Jordanian population: A computed tomographic study

There is a paucity of osteometric standards for sex estimation from unknown skeletal remains in Jordan and the sexual dimorphism of the sternum has not yet been investigated. The aim of this study was to evaluate the sexual dimorphism in sternal measurements using 3D multidetector computed tomography (MDCT), and to assess their reliability for sex estimation in a Jordanian population. A total of 600 MDCT scans (300 males and 300 females) were used and a total of 8 sternal measurements were studied (manubrium length, sternal body length, combined length of manubrium and body, corpus sterni width at 1st and 3rd sternebrae, sternal index and area). Sexual dimorphism was evaluated by means of discriminant function analyses. Significant sexual dimorphism was found mainly in middle-aged and older adults. Including all subjects, multivariate, and stepwise functions gave an overall accuracy of 83.0% and 84.0%, respectively. Additionally, multivariate and stepwise analyses were conducted separately for each age group. The accuracy of sex estimation in multivariate analysis (all variables) varied from 63.2% in the young, and 83.7% in the middle adults to 84.9% for older adults. In stepwise analysis, the highest accuracy rates were provided by only sternal area in young adults (81.6%), and sternal area combined with sternal body length in middle-aged and older adults (84.2% and 85.3%, respectively). The best sex discriminator using univariate analysis (single variable) was sternal area followed by sternal body length (84.0% and 80.8% respectively). Notably, univariate analyses for most variables gave relatively higher classification accuracies in females but were poor at predicting males in the sample (sex bias ranged between -6.4% and -20%). Our data suggest that dimorphism in the human sternum increases with advancing age and separate discriminant functions are needed for each age group in Jordanians. In addition, multivariate and stepwise analyses using sternum gave higher classification accuracies with comparatively lower sex biases compared to univariate analyses.

Pair-Matching Digital 3D Models of Temporomandibular Fragments Using Mesh-To-Mesh Value Comparison and Implications for Commingled Human Remain Assemblages

The mesh-to-mesh value comparison (MVC) method developed by Karell et al. (Int J Legal Med 130(5):1315-1322, 2016) facilitates the digital comparison of three-dimensional mesh geometries obtained from laser-scanned or computed tomography data of osteological materials. This method has been employed with great success to pair-matching geometries of intact skeletal antimeres, that is, left and right sides. However, as is frequently the case for archaeological materials, there are few circumstances which proffer complete skeletal remains and fewer still when considering contexts of commingling. Prior to the present research, there existed a paucity of sorting techniques for the diverse taphonomic conditions of skeletal materials found within commingled assemblages, especially regarding fragmentary remains. The present chapter details a study in which the MVC method was adapted to encompass comparisons of isolated components of bone in lieu of entire bone geometries in order to address this dearth. Using post-mortem computed tomography data from 35 individuals, three-dimensional models of 70 mandibular fossae and 69 mandibular condyles were created and then compared using Viewbox 4, to produce numerical mesh-to-mesh values which indicate the geometrical and spatial relationship between any two given models. An all-to-all comparison was used to determine if the MVC method, using an automated Trimmed Iterative Closest Point (TrICP) algorithm, could be utilized to (1) match corresponding bilateral pairs of condyles and fossae and (2) match same-sided articular correlates. The pair-matching of both the condyles and the fossae generally produced high sensitivity and specificity rates. However, the articulation results were much poorer and are not currently recommended.

Disaster victim identification operations with fragmented, burnt, or commingled remains: experience-based recommendations

Human-made and natural disasters can result in severely fragmented, compromised, and commingled human remains. The related disaster victim identification (DVI) operations are invariably challenging, with the state of the remains potentially precluding some identifications. Practitioners involved in these DVI operations will routinely face logistical, practical, and ethical challenges. This review provides information and guidance derived from first-hand experiences to individuals tasked with managing DVI operations with fragmented human remains. We outline several key issues that should be addressed during disaster preparedness planning and at the outset of an operation, when incident-specific strategies are developed. Specific challenges during recovery and examination of fragmented remains are addressed, highlighting the importance of experienced specialists at the scene and in the mortuary. DNA sample selection and sampling techniques are reviewed, as well as downstream effects of commingling and contamination, which can complicate reconciliation and emphasise the need for rigorous quality control. We also touch on issues that may arise during communication with families. While recommendations are provided, they are not intended as proscriptive policy but rather as an addition to the general recommendations given in the International Criminal Police Organization (INTERPOL) DVI Guide, to inform preparative discussions between government officials, judiciary, police, and forensic specialists.

Key points

A DVI operation for an incident characterised by many fragmented and otherwise compromised human remains poses specific challenges that may prolong and complicate identifications.

Specialists should be consulted at the outset to address key issues related to the aim and extent of the operation.

Specialist expertise in handling compromised human remains is indispensable at the scene, in the mortuary, during reconciliation, and for quality control.

Continuous consultation between representatives from government, the judiciary, law enforcement, the media, and various forensic specialists will prevent unnecessary delay and facilitate accurate and timely communication.

Mastoid, middle ear and inner ear analysis in CT scan - a possible contribution for the identification of remains

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.

Communicating 3D data-interactive 3D PDF documents for expert reports and scientific publications in the field of forensic medicine

INTRODUCTION

Modern forensic investigations increasingly revert to 3D imaging techniques, such as computed tomography, magnetic resonance imaging, and 3D surface imaging. Findings are therefore often based on 3D data sets; however, this information is commonly reported and communicated within 2D imagery. The use of interactive 3D PDFs is already established in the scientific community but has yet to be implemented in the field of forensic medicine.

METHODS AND MATERIALS

Three example cases were chosen to serve as exemplary data for the most commonly applied imaging techniques in postmortem imaging. 3D surface models were created from postmortem magnetic resonance imaging (PMMR), postmortem computed tomography (PMCT), and 3D surface imaging data sets.

RESULTS

PMMR revealed a space-occupying subdural hemorrhage that led to ipsilateral compression of the brain tissue of the right hemisphere. PMCT displayed a defect in the skull on the left side of the temporal bone. 3D surface imaging data displayed a patterned discoloration on the inside of the left forearm.

DISCUSSION

Interactive 3D PDFs offer the possibility to communicate 3D information to the reader while maintaining all the benefits of a regular 2D PDF. With Adobe Acrobat, the reader can interactively navigate through 3D data sets and create sufficient depth cues to generate a realistic 3D perception of the data.

CONCLUSION

The interactive 3D PDF is a useful extension of standard 2D PDFs and has the potential to communicate 3D data to the reader in a more complete, more comprehensible, and less subjective manner than 2D PDFs.

Baggage scanners and their use as an imaging resource in mass fatality incidents

Disaster victim identification following a mass fatality incident is focussed on identifying the deceased and returning them to their families as quickly as possible, while gathering as much information as practical to aid investigators in establishing the cause of the incident. Ante-mortem data is gathered and compared with the post-mortem data obtained in order to positively identify the deceased. This paper presents results from a study concerned with the first part of the process of identifying the deceased—the triage or Primary Survey and how this can be done without access to hospital facilities such as conventional X-ray imaging or computed tomography. In particular, this study focuses on the imaging undertaken prior to the opening of the body bag by a multidisciplinary team, and how this imaging can assist particularly when forensic anthropologists are involved in the identification process. There are several advantages to imaging the body bags before they are opened and one of the most important is safety. Thus, this paper examines the viability of using a baggage scanner as a practical resource for X-ray imaging, as many regions worldwide may not be able to access conventional imaging equipment. Baggage scanners are readily available and found in airports and various government buildings. The baggage scanner is particularly suited to this task and produces images that can be used by forensic anthropologists to distinguish between human and non-human remains, identify items of evidence and personal effects, and even perform a preliminary or partial biological profile. When considering their response plans, emergency responders should consider including baggage scanners as a contingency for screening body bags if no other imaging system is available.

Evaluation of the applicability of regression equations for sorting commingled remains on 3-Dimensional bony elements from CT scans

This pilot study examines the applicability of osteometric models for addressing commingled remains, which were originally developed for dry specimens, on 3-Dimensional bony elements in relation to a modern cadaveric population. A total of 70 bony elements (humeri, radii, ulnae, femora, tibiae and fibulae) were segmented and virtually reconstructed from cadaveric whole-body CT scans. Linear measurements were taken (using MeshLab v.2016.12) of the 3-Dimensional elements and osteometric models for sorting applied to them (Byrd and Adams, 2003). This study showed that on the selected specimens the quality of the surface of the reconstructed specimens compromised the efficacy of the models, and consequently the reliability of the results.

Forensic anthropology in the global investigation of humanitarian and human rights abuse: Perspective from the published record

Forensic anthropologists have played key roles in the historical development of forensic science applications to global humanitarian and human rights issues. These anthropological initiatives can be traced back to the Smithsonian seminar organized by T. D. Stewart in 1968 and published in 1970. Key developments include the 1984 delegation sent by the American Association for the Advancement of Science to Argentina and the formation of the Argentine Forensic Anthropology Team. Subsequent highlights include major anthropological involvement in support of investigations by international criminal tribunals, formation of forensic anthropology teams in different countries and activities of the International Commission of Missing Persons and the forensic unit of the International Committee of the Red Cross. Recent developments feature the formation of the Humanitarian and Human Rights Resource Center of the American Academy of Forensic Sciences and its support of worthwhile projects in many countries. The published record provides historical perspective on these developments.

Searching for Kin Amidst Tragedy-Disaster Victim Identification Operations for US Bangla Flight 211

The nature of air disasters includes factors that exacerbate challenges in the identification process. Of the 49 deceased in the US Bangla air crash in Kathmandu, Nepal, four were intact, 11 presented with burn injuries, another 11 presented with partial charring, and 23 were completely charred. Personal belongings were useful in the identification phases for all types of victims. Fingerprints were obtainable and useful in intact victims and victims with less severe burn injuries; medical and surgical information was useful in bodies with burn injuries; finally, dental findings were useful in cases of extensive charring. Other useful methods in the process included marks of identification, physical features, and exclusion. In certain resource-limited settings, especially in closed population disasters, where scientific identification (DNA, dental records, etc.) is not currently available, personal belongings, clothing, and physical findings analyzed by an identification team using a structured organization may be cautiously used as the primary means of identification.

The role of forensic anthropology in disaster victim identification (DVI): recent developments and future prospects

Forensic anthropological knowledge has been used in disaster victim identification (DVI) for over a century, but over the past decades, there have been a number of disaster events which have seen an increasing role for the forensic anthropologist. The experiences gained from some of the latest DVI operations have provided valuable lessons that have had an effect on the role and perceived value of the forensic anthropologist as part of the team managing the DVI process. This paper provides an overview of the ways in which forensic anthropologists may contribute to DVI with emphasis on how recent experiences and developments in forensic anthropology have augmented these contributions. Consequently, this paper reviews the value of forensic anthropological expertise at the disaster scene and in the mortuary, and discusses the way in which forensic anthropologists may use imaging in DVI efforts. Tissue-sampling strategies for DNA analysis, especially in the case of disasters with a large amount of fragmented remains, are also discussed. Additionally, consideration is given to the identification of survivors; the statistical basis of identification; the challenges related to some specific disaster scenarios; and education and training. Although forensic anthropologists can play a valuable role in different phases of a DVI operation, they never practice in isolation. The DVI process requires a multidisciplinary approach and, therefore, has a close collaboration with a range of forensic specialists.

Estimating Sex Using Metric Analysis of the Scapula by Postmortem Computed Tomography

Postmortem computed tomography (CT) has been extensively used in the last decade for identification purposes and in various anthropologic studies. Postmortem CT measurements of scapulae, analyzed using logistic discriminant function developed in this study, showed 94.5% accuracy in estimating sex. Data analyzed using the Dabbs and Moore-Jansen (2010) discriminant function and the discriminant function generated in this study provided nearly identical results with disagreement in only one case. Height and weight were not statically significant in sex prediction. The results of this study show that data obtained from volume rendered postmortem CT images can be considered reliable and treated as a practical option to standard anthropological methods, especially in mass fatalities as a rapid triage tool for sex determination.

Standardized medical image registration for radiological identification of decedents based on paranasal sinuses

Image registration software is frequently used in clinical radiology, e.g., for follow-up diagnosis. To a certain extent, the radiological identification of decedents (RadID) is comparable to a clinical follow-up diagnosis, in that two datasets from different dates are compared in terms of their anatomical characteristics (e.g., paranasal sinuses) or surgical implants. Due to the increasing use of computed tomography (CT) for head examinations in clinical radiology and the increased use of postmortem CT (PMCT) in forensic imaging, the comparison of three-dimensional (3D) clinical CT (termed as antemortem CT (AMCT) in this article) and PMCT datasets for RadID is becoming increasingly practical. In particular, the comparison of paranasal sinuses in AMCT and PMCT imaging is considered a suitable and reliable modality for RadID. However, previous publications regarding RadID based on comparisons of 3D datasets have not considered the implementation of image registration to provide software-side support for RadID. This article demonstrates and evaluates the use of a standard medical image registration procedure for RadID by comparing paranasal sinuses.

Virtual anthropology - a brief review of the literature and history of computed tomography

Computed tomography (CT) has influenced numerous fields since its inception in the 1970s. The field of palaeoanthropology significantly benefited from this efficient and non-invasive medium in terms of the conservation, reconstruction and analysis of fossil human remains. Over the past decade, there has been a steady increase in the number of forensic anthropological studies incorporating virtual osteological analyses. Because of the increasing importance of these modern cross-sectional imaging techniques and the requirement for standardized parameters in forensic science, we deemed it important to outline the history and development of CT applications in these related academic areas. The present paper outlines the history of “virtual anthropology” and osteological multi-detector CT in the context of palaeoanthropology and forensic anthropology.

Sex Estimation from Human Cranium: Forensic and Anthropological Interest of Maxillary Sinus Volumes

Sex estimation is a key objective of forensic science. We aimed to establish whether maxillary sinus volumes (MSV) could assist in estimating an individual's sex. One hundred and three CT scans were included. MSV were determined using three-dimensional reconstructions. Two observers performed three-dimensional MSV reconstructions using the same methods. Intra- and interobserver reproducibility were statistically compared using the intraclass correlation coefficient (ICC) (α = 5%). Both intra- and interobserver reproducibility were perfect regarding MSV; both ICCs were 100%. There were no significant differences between right and left MSV (p = 0.083). No correlation was found between age and MSV (p > 0.05). We demonstrated the existence of sexual dimorphism in MSV (p < 0.001) and showed that MSV measurements gave a 68% rate of correct allocations to sex group. MSV measurements could be useful to support sex estimation in forensic medicine.

Critical issues in the historical and contemporary development of forensic anthropology in Australia: An international comparison

The aim of this brief critical qualitative analysis is to examine the development of forensic anthropology in Australia, at a time of significant change in the discipline. It will briefly summarise its historical establishment, making comparative reference to other regions-particularly the United Kingdom and United States, and the influence of the Bali Bombings of 2002, Indian Ocean earthquake and tsunami of 2004 and Black Saturday Bushfires of 2009. The analysis goes on to consider key factors in research in forensic anthropology in the United States, and the development of standards and regulation in the US and UK. The significance of research in post-mortem diagenesis in Brazil-a country sharing aspects of climate, soil types and demography with Australia-is also considered, as well as the significance of patterns of casework encountered in Australia compared with those of other jurisdictions. While forensic anthropology as a discipline has grown remarkably in recent years, this analysis suggests that research and training tailored to the specific pattern of casework encountered in Australia is now essential to support the development of national standards in science, education, and professional regulation. The significance of the establishment of the first taphonomy research facility outside of the US-the Australian Facility for Taphonomic Experimental Research-is briefly considered with reference to what this facility may offer to the development of forensic anthropology in Australia.

The effect of common imaging and hot water maceration on DNA recovery from skeletal remains

Identifying human remains often begins with cleaning and imaging the material. Hot water maceration is used to remove adherent soft tissue from bone and radiographs are taken to better visualize osseous details. Heat and radiation are known to have harmful effects on DNA, but their ability to degrade DNA when used for cleaning and imaging has not been well studied. To better understand their individual and combined effects on the recoverability of DNA from bone, skeletal samples were subjected to (1) hot water maceration (62 °C for 45 min); (2) CT scanning (0.6mm slices, 120 kV, 10.4s); (3) X-ray (50 kVp, 150 mA, 0.03 s, 40 in); and (4) all 3 treatments combined. Forty-eight DNA samples were extracted, quantified and amplified with the AmpFLSTR(®) Identifiler(®) system. Nearly all of the processed samples had reduced RFU values relative to the unprocessed samples, indicating some amount of genetic loss. This loss did not always translate into loss of profile completeness, since only a few samples had a reduction in the number of loci detected after processing. DNA yields were not significantly reduced by any one of the processing methods, however the results indicate that the damaging effects are additive. It is possible that processing may reduce a bone's DNA reservoir and as more procedures are preformed, the pool of available genetic information might be diminished. Many intrinsic and extrinsic factors can affect the recoverability of DNA from bone. Collecting a DNA sample prior to processing avoids the negative effects from hot water maceration and radiological imaging.

A new computer-tomography-based method of sex estimation: Development of Turkish population-specific standards

The identification of victims involved in mass fatality incidents has become an increasingly important issue nowadays, and identification of unknown individuals is an important aspect in criminal cases and Disaster Victim Identification scenarios. Therefore, the sex estimation is one of the most important biological attributes towards establishing personal identity. In addition, several studies have demonstrated that metric sex determination methods of the skeleton are population-specific due to variation in size and patterns of sexual dimorphism. Unfortunately, the modern Turkish population still lacks wide and representative population standards for identification. Previous research has shown that modern technologies, such as CT scanning appear to offer promising means for the establishment of new standards for contemporary populations. The main aim of this project is to examine the application of measurements taken from the femur in order to assess sex, as well as to contribute to the establishment of discriminant function equations for the Turkish population for forensic applications. The sample population was composed of CT images taken from 200 adult hospital patients. The images of the femora were segmented from the surrounding bones to ensure correct usage of landmarks as accurately as possible. The 3D reconstructions were then created using the volume-rendering function in OsiriX (v.5.6.). Thirteen measurements were acquired using a 3D viewer and were located and marked on each of the CT reconstructed femora. Thirteen anthropometric parameters were measured and analysed by basic descriptive statistics and discriminant analysis methods using the SPSS 21.0 software package. The intra-observer variation was assessed by obtaining the inter-cross correlation coefficient in order to evaluate the accuracy of the linear measurements taken. The accuracy of sex prediction ranged from 63.5 to 88% with single variables. In stepwise analysis, Epicondylar Breadth, Femur Vertical Diameter of Neck and Medial Lateral Subtrochanteric Diameter were found to be the most discriminating variables providing an accuracy of 91%. Ultimately, it is envisaged that this research study will produce data and interpretations that will inform on and improve standards of sex estimation from postcranial osteometric landmarks. Additionally, this research will consider how this data provides value for a developing discipline of forensic anthropology and how it integrates within the existing systems of criminal investigation and Disaster Victim Identification practices in Turkey.

Determination of sex: interest of frontal sinus 3D reconstructions

Frontal sinuses (FSs) have been studied in radiology, anthropology, and forensic anthropology. This study aimed to determine whether it was possible to predict the age and sex of an individual using FS volume. Sixty-nine anonymized CT scans were imported to MIMICS 10.01(®) software (Materialise N.V.), and each FS volume was calculated in mm(3) . There was an absence of significant difference between right and left FS volume (p = 0.173) and an absence of correlation between age and FS volume (Pearson's test; p = 0.705). Sexual dimorphism was significantly different (p = 0.001). However, the most discriminant datum for determining sex was found to be the total FS volume (sum of an individual's right and left FS volumes) with linear discriminant Fisher's function coefficients of -2.759 for the male group and -1.275 for the female group. With this model, 72.5% of our sample was correctly classified according to sex.

Adult post-mortem imaging in traumatic and cardiorespiratory death and its relation to clinical radiological imaging

The use of post-mortem imaging is expanding throughout the world with increasing use of advanced imaging techniques, such as contrast-enhanced CT and MRI. The questions asked of post-mortem imaging are complex and can be very different, for example for natural sudden death investigation will focus on the cause, whereas for trauma the cause of death is often clear, but injury patterns may be very revealing in investigating the background to the incident. Post-mortem imaging is different to clinical imaging regarding both the appearance of pathology and the information required, but there is much to learn from many years of clinical research in the use of these techniques. Furthermore, it is possible that post-mortem imaging research could be used not only for investigating the cause of death but also as a model to conduct clinically relevant research. This article reviews challenges to the development of post-mortem imaging for trauma, identification and cardiorespiratory death, and how they may be influenced by current clinical thinking and practice.

Use of pacemaker programmers for disaster victim identification

Disaster victim identification (DVI) presents a number of physical and legal challenges, involving the degeneration of human remains and legal obstacles to forensic examinations. One non-invasive method for positive identification may be the use of a pacemaker programmer to detect and obtain data from pacemakers recovered from unidentified remains. To test the usefulness of this method, this investigation examined the efficiency and utility of 5 different pacemaker programmers in the positive identification of victims of the March 2011 tsunami in Japan at 8 disaster sites in May 2011. On scanning 148 sets of remains, data were successfully obtained from 1 implant in 1 set of remains, allowing for the rapid positive identification of the individual. Scanning pacemakers with pacemaker programmers can be a non-invasive method of positive identification that meets Japanese legal and institutional requirements, but this method is ineffective without a preceding whole-body X-ray scan.

The conclusive role of postmortem computed tomography (CT) of the skull and computer-assisted superimposition in identification of an unknown body

Computed tomography is commonly used in modern medicine, and thus, it is often helpful for medicolegal purposes, especially as part of the antemortem record. The application of postmortem computed tomography and 3D reconstruction of the skull in challenging cases is reported, and its valuable contribution to positive identification is discussed. This paper presents a case in which the body of an unknown individual is identified. Positive identification had not been possible despite a multidisciplinary examination. The postmortem use of computerized tomography and 3D reconstruction of the skull followed by the comparison of individual morphological characteristics of the viscerocranium showed the concordant points between the deceased and a missing person. Finally, superimposition using a 3D-reconstructed skull instead of the skeletonized skull demonstrated an adequate degree of morphological consistency in the facial images of the analyzed individuals that lead to positive identification. It was concluded that where other methods of personal identification had failed, the use of postmortem computed tomography had proved to be instrumental in the positive identification of the deceased.

Integrating forensic anthropology into Disaster Victim Identification

This paper will provide mass fatality emergency planners, police, medical examiners, coroners and other Disaster Victim Identification (DVI) personnel ways to integrate forensic anthropologists into DVI operations and demonstrate how anthropological contributions have improved DVI projects. In mass disaster situations, anthropologists have traditionally been limited to developing biological profiles from skeletal remains. Over the past decade, however, anthropologists' involvement in DVI has extended well beyond this traditional role as they have taken on increasingly diverse tasks and responsibilities. Anthropological involvement in DVI operations is often dictated by an incident's specific characteristics, particularly events involving extensive fragmentation, commingling, or other forms of compromised remains. This paper will provide examples from recent DVI incidents to illustrate the operational utility of anthropologists in the DVI context. The points where it is most beneficial to integrate anthropologists into the DVI process include: (1) during recovery at the disaster scene; (2) at the triage station as remains are brought into the mortuary; and (3) in conducting the reconciliation process. Particular attention will be paid to quality control and quality assurance measures anthropologists have developed and implemented for DVI projects. Overall, this paper will explain how anthropological expertise can be used to increase accuracy in DVI while reducing the project's cost and duration.

Postmortem X-ray Computed Tomography (CT) and Forensic Autopsy: A Review of the Utility, the Challenges and the Future implications

The utility of computed tomography (CT) for forensic autopsy is being defined. Small studies have indicated potential areas of use. Systematic studies are few. Evidence of the utility of CT as an autopsy substitute in fatal trauma cases has been inconsistent. Some studies show that there are injuries seen by CT that aren't detected by autopsy indicating that CT, at least, is likely useful as an autopsy adjunct. Research has been limited by small study populations, variation in postmortem interval, differences in protocols including CT slice thickness, who interpreted the scans (radiologists vs. pathologists), and how injuries were scored. Challenges exist to implement and use advanced imaging technology for the forensic autopsy. It is important to determine how to arrange these technologies into a coherent approach to postmortem diagnosis while not encumbering forensic pathologists. Forensic pathologists and radiologists require training in interpreting the unique aspects of postmortem CT scans. Some forensic pathologists might perceive imaging technology as a threat and express concern that it will make the autopsy obsolete.

If CT is found to supplant or supplement autopsy in valuable ways, more comprehensive diagnostic information can be provided. If CT can supplant the use of autopsy in certain situations and significantly decrease autopsy numbers it will allow offices to achieve an annual cost savings and divert these resources to other needs. If CT becomes widely available and can supplant autopsy, it could make up some of the gap between the numbers of forensic pathologists available and the numbers needed nationally.

A state-of-the-art pipeline for postmortem CT and MRI visualization: from data acquisition to interactive image interpretation at autopsy

The importance of autopsy procedures leading to the establishment of the cause of death is well-known. A recent addition to the autopsy work flow is the possibility of conducting postmortem imaging, in its 3D version also called virtual autopsy (VA), using multidetector computed tomography (MDCT) or magnetic resonance imagining (MRI) data from scans of cadavers displayed with direct volume rendering (DVR) 3D techniques. The use of the data and their workflow are presented. Data acquisition was performed and high quality data-sets with submillimeter precision were acquired. New data acquisition techniques such as dual-energy CT (DECT) and quantitative MRI, then were implemented and provided additional information. Particular findings hardly visualized in conventional autopsy can rather easy be seen at the full body CT, such as air distribution, e.g. pneumothorax, pneumopericardium, air embolism, and wound channels. MRI shows natural deaths such as myocardial infarctions. Interactive visualization of these 3D data-sets can provide valuable insight into the corpses and enables non-invasive diagnostic procedures. In postmortem CT imaging, not being limited by a patient depending radiation dose limit the data-sets can, however, be generated with such a high resolution that they become difficult to handle in today's archive retrieval and interactive visualization systems, specifically in the case of full body scans. To take full advantage of these new technologies the postmortem workflow needs to be tailored to the demands and opportunities that the new technologies allow.

Gender determination from hand bones length and volume using multidetector computed tomography: a study in Egyptian people

Determination of sex from incomplete skeletal and decomposing human remains is particularly important in personal identification. Measurements of hand bones length have been shown to be sexually dimorphic in many nationalities. Since the validity of discriminant function equation in sex determination is population specific; the purpose of this study is to assess sex from the hand bones length in a contemporary Egyptian population using data derived from both multiplanar (two-dimensional) and volumetric (three-dimensional) reformatted images of multidetector CT to derive special equations for sex determination in Egyptians. One hundred and twenty two Egyptians (60 males and 62 females) with mean age of 24.1 ± 4.4 were included. An independent samples student's t-test and discriminant function analysis were done. Results indicate existence of length differences between the sexes. Males presented with significantly greater mean values than females for distal phalanges of all fingers, 1st and 3rd proximal phalanges and all metacarpal bones measured by 2D images. Metacarpals, proximal phalanges and distal phalanges are sexually dimorphic with accuracies of 80%, 76.6% and 80% respectively. Three-dimensional volume-rendered reconstructed images of metacarpals give more accurate results (92.9%) in correct sex determination when compared with 2D images. From the forensic standpoint, the usefulness of this study rests on the identification of sex among Egyptian based on length and volume differences observed on MDCT examination.

Forensic radiology and personal identification of unidentified bodies: a review

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.

Evaluation of computed tomography as a screening test for death inquest

The Japanese method of inquest, which depends mostly on external examinations, may misdiagnose a considerable number of accidental deaths and suicides as death by disease. We conducted computed tomography (CT) scans of 80 cases for which police concluded death by disease or natural causes based on police investigations into the circumstances and results from external examinations. The cause of death was clearly determined by CT scan in 17 of 80 cases. Ten cases underwent autopsy after the police suspected criminality based on results of the CT examinations. The results suggest CT scan may be a tool for preventing a number of overlooked crimes and accidents in Japan. However, it cannot be a perfect tool for discerning between death by disease and other causes of death without cooperation from the investigative agencies and subsequent forensic examinations such as autopsy and toxicological tests.

Radiologic identification of disaster victims: a simple and reliable method using CT of the paranasal sinuses

OBJECTIVE

To assess the reliability of radiologic identification using visual comparison of ante and post mortem paranasal sinus computed tomography (CT).

SUBJECTS AND METHODS

The study was approved by the responsible justice department and university ethics committee. Four blinded readers with varying radiological experience separately compared 100 post mortem to 25 ante mortem head CTs with the goal to identify as many matching pairs as possible (out of 23 possible matches). Sensitivity, specificity, positive and negative predictive values were calculated for all readers. The chi-square test was applied to establish if there was significant difference in sensitivity between radiologists and non-radiologists.

RESULTS

For all readers, sensitivity was 83.7%, specificity was 100.0%, negative predictive value (NPV) was 95.4%, positive predictive value (PPV) was 100.0%, and accuracy was 96.3%. For radiologists, sensitivity was 97.8%, NPV was 99.4%, and accuracy was 99.5%. For non-radiologists, average sensitivity was 69.6%, negative predictive value (NPV) was 91.7%, and accuracy was 93.0%. Radiologists achieved a significantly higher sensitivity (p < 0.01) than non-radiologists.

CONCLUSIONS

Visual comparison of ante mortem and post mortem CT of the head is a robust and reliable method for identifying unknown decedents, particularly in regard to positive matches. The sensitivity and NPV of the method depend on the reader's experience.

The use of computed tomography (CT) to estimate age in the 2009 Victorian Bushfire Victims: a case report

The development of new imaging technologies is beginning to have an impact upon medico-legal death investigation in an increasing number of jurisdictions. Computed tomography (CT) is an imaging modality which is able to provide information to investigators without the need for a physically invasive autopsy in certain circumstances. The use of post-mortem CT as an aid to the identification of the victims of the Black Saturday bushfires is discussed with particular reference to dental age estimation. A case report is presented which demonstrates the ability of this imaging modality to separate individuals based upon dental development. Whilst CT is not yet able to adequately discriminate between differing restoration types and shapes, and therefore cannot be used for dental identification in the classic sense, the ability of this imaging modality to assess dental and skeletal development for the purpose of age estimation is valid.

Contribution of postmortem multidetector CT scanning to identification of the deceased in a mass disaster: Experience gained from the 2009 Victorian bushfires

CT scanning of the deceased is an established technique performed on all individuals admitted to VIFM over the last 5 years. It is used primarily to assist pathologists in determining cause and manner of death but is also invaluable for identification of unknown deceased individuals where traditional methods are not possible. Based on this experience, CT scanning was incorporated into phase 2 of the Institute's DVI process for the 2009 Victorian bushfires. All deceased individuals and fragmented remains admitted to the mortuary were CT scanned in their body bags using established protocols. Images were reviewed by 2 teams of 2 radiologists experienced in forensic imaging and the findings transcribed onto a data sheet constructed specifically for the DVI exercise. The contents of 255 body bags were examined in the 28 days following the fires. 164 missing persons were included in the DVI process with 163 deceased individuals eventually identified. CT contributed to this identification in 161 persons. In 2 cases, radiologists were unable to recognize commingled remains. CT was utilized in the initial triage of each bag's contents. If radiological evaluation determined that bodies were incomplete then this information was provided to search teams who revisited the scenes of death. CT was helpful in differentiation of human from non-human remains in 8 bags, recognition of human/animal commingling in 10 bags and human commingling in 6 bags. In 61% of cases gender was able to be determined on CT using a novel technique of genitalia detection and in all but 2 cases this was correct. Age range was able to be determined on CT in 94% with an accuracy of 76%. Specific identification features detected on CT included the presence of disease (14 disease entities in 13 cases), medical devices (26 devices in 19 cases) and 274 everyday metallic items associated with the remains of 135 individuals. CT scanning provided useful information prior to autopsy by flagging likely findings including the presence of non-human remains, at the time of autopsy by assisting in the localization of identifying features in heavily disfigured bodies, and after autopsy by retrospective review of images for clarification of issues that arose at the time of pathologist case review. In view of the success of CT scanning in this mass disaster, DVI administrators should explore the incorporation of CT services into their disaster plans.

Release of metals from osteosynthesis implants as a method for identification: post-autopsy histopathological and ultrastructural forensic study

Metal structures--especially of stainless steel, titanium and their alloys (biomaterials)--are widely used in orthopaedic practice and the subject of constant study in bioengineering and preventive medicine. This study presents the first experience of forensic research into the presence of permanent tissue variations around metal implants in various bone structures for the purpose of identification, with particular reference to skeletal remains or severely decomposed corpses in the absence of other identifying elements. The evaluation was conducted on 12 corpses who had undergone osteosynthesis intra-vitam, whose implants were still in place or had been removed, in comparison with five controls who had never undergone osteosynthesis. Bone fragments taken during autopsy were subjected to histopathological and scanning electron microscope-energy dispersive electroscopy examination in order to reveal and characterise any metal particles originating from osteosynthesis. The study enabled the discovery of intra-bone metal particles in tissues treated by osteosynthesis even in bone areas where the implants had been removed and even where there were no longer any radiological signs of their application. These results are therefore of considerable forensic importance, especially in the area of identification, providing a valid means of recognition beyond that of the well-established use of in situ metal implants.