Age at Death Estimation Using Multislice Computed Tomography Reconstructions of the Posterior Pelvis*

Abstract: Thanks to recent advances, computed tomography is now seen as a tool of great value in the field of physical anthropology. In this study, we focused on the posterior pelvis and the auricular surface and evaluated the accuracy of 3D reconstructions of the auricular surface, using a methodology derived from a previous study by Lovejoy et al. We also looked for trabecular bone criteria expressing age‐related changes. Forty‐six coxal bones were scanned, and scoring of macroscopic criteria showed a good agreement between 3D reconstructions and photographs, especially for transverse organization (k = 0.90). The changes occurring in the posterior part of the sacropubic trabecular bundle were evaluated on CT reconstructions via three new criteria, which exhibited a good intra‐ and inter‐observer agreement (k = 0.77–0.89), and were particularly useful in identifying older subjects. We concluded that these CT‐evaluated trabecular bone criteria are promising and yield useful information about age at death.     

Sexual Dimorphism of the Fetal Ilium: A 3D Geometric Morphometric Approach with Multislice Computed Tomography

Adult sexual dimorphism is well established. However, data regarding fetuses are sparse with contradictory results. Our study aimed to look for fetal sexual dimorphism. Multislice computed tomography (MSCT) examinations and three‐dimensional (3D) reconstructions were recorded on 93 fetal iliac bones aged between 21 and 40 weeks of amenorrhea (WA). The collection was divided into two age groups, with a cutoff at 30 WA. The 3D geometric morphometric analysis was based on outline analysis. We used elliptic Fourier analysis (EFA) because of the difficulty of landmark positioning. Step‐by‐step reconstructions allowed a better comprehension of the fine shape details. Principal component analysis (PCA) and linear discriminant analysis (LDA) were performed on the two age groups. Results did not show any difference between male and female shapes, in both age groups. We demonstrate the feasibility of outline analysis for immature shapes, but sexual dimorphism has not been established in our collection.     

Postmortem chest computed tomography for the diagnosis of drowning:a feasibility study

It may be difficult to distinguish the cause of death in drowning cases without specific findings. The aim of this study was to explore the forensic value of thoracic postmortem computed tomography (PMCT) using routine images and three-dimensional (3D) image reconstructions. The imaging data of PMCT examinations of six drowning cadavers, aged 21–54 years, were analyzed. Twelve victims of sudden death from coronary artery disease (CAD) were chosen as a control group. After 3D bilateral lung images were reconstructed using image processing software, an interactive medical image control system was used to measure and analyze parameters including lung volume, lung volume ratio, mean CT value of the whole lung, and lung CT value distribution curves. Lung volume and lung volume ratio were used to assess the shape changes of the lung. Lung CT value distribution curves showed the corresponding number of pixels of the different CT values in the lung image. Lung volume was not significantly larger in drowning cases (mean 2 958 cm³) than in controls (mean 2 342 cm³). Lung volume ratio values in the drowning group (mean 0.3156) were greater than those in the control group (mean 0.2763); (P = 0.02). There was no significant difference between the drowning and control group in the mean CT value of the whole lung. There were differences between lung CT value distribution curves in drowning victims and controls, with drowning victims showing a single peak and CAD cases showing a bimodal distribution. Thoracic PMCT is helpful for the forensic medical diagnosis of drowning. Lung volume ratio and lung CT value distribution are potential indicators to distinguish between drowning and CAD.     

High-quality Digital 3D Reconstruction of Microscopic Findings in Forensic Pathology: The Terminal Pathway of a Heart Stab Wound*

High-quality digital three-dimensional (3D) reconstructions of microscopic findings have been used in anatomical and histopathologic research, but their use in forensic pathology may also be of interest. This paper presents an application of these methods to better characterize the pathway of a stab wound of the anterior surface of the heart in a case of suicide. A portion of the heart wall including the stab wound was serially sectioned for microscopic analysis along the full extent of the wound. Histologic sections were digitally acquired, and a 3D reconstruction was created with ImageJ software for 3D computer graphics. This showed a full-thickness wound path extending to the endocardial surface of the left ventricle, curvilinear in appearance. After correction for shrinkage, 3D reconstruction allowed estimation of the dimensions of the myocardial injury and comparison of the appearance of the wound with the suspected knife used. The curvilinear appearance was considered to reflect injury during myocardial contraction. Complete microscopic sectioning and 3D reconstruction may allow virtual sectioning through various orientations and also provide useful forensic information for selected injuries.     

Pubic Symphyseal Age Estimation from Three‐Dimensional Reconstructions of Pelvic CT Scans of Live Individuals

Skeletal age estimation using the pubic symphysis is a reliable and popular practice among forensic anthropologists. In instances in which accessing the skeleton is impossible, such as in the case of living individuals, three‐dimensional (3D) reconstructions of computed tomography (CT) scans can be created and analyzed for aspects of the biological profile. This study examined 3D reconstructions of pelvic CT scans of a sample of 44 live adults to estimate age using the Suchey–Brooks J Hum Evol 1990;5(3):227‐38 method. Images were created using OsiriX software (Pixmeo, Geneva, Switzerland). Estimated age ranges based on the 3D‐CT images captured the true age of the individual at the time of the CT scan 79.5% of the time with good intra‐observer reliability. The features best visualized on the 3D images included the ossific nodule and the pubic symphyseal rim. This study shows that clinical CT scanning parameters are adequate for creating 3D images to be analyzed for age using the pubic symphysis.     

An accuracy assessment of forensic computerized facial reconstruction employing cone-beam computed tomography from live subjects

The utilization of 3D computerized systems has allowed more effective procedures for forensic facial reconstruction. Three 3D computerized facial reconstructions were produced using skull models from live adult Korean subjects to assess facial morphology prediction accuracy. The 3D skeletal and facial data were recorded from the subjects in an upright position using a cone-beam CT scanner. Shell-to-shell deviation maps were created using 3D surface comparison software, and the deviation errors between the reconstructed and target faces were measured. Results showed that 54%, 65%, and 77% of the three facial reconstruction surfaces had <2.5 mm of error when compared to the relevant target face. The average error for each reconstruction was -0.46 mm (SD = 2.81) for A, -0.31 mm (SD = 2.40) for B, and -0.49 mm (SD = 2.16) for C. The facial features of the reconstructions demonstrated good levels of accuracy compared to the target faces.     

Reliable Gait Recognition Using 3D Reconstructions and Random Forests – An Anthropometric Approach

Photogrammetric measurements of bodily dimensions and analysis of gait patterns in CCTV are important tools in forensic investigations but accurate extraction of the measurements are challenging. This study tested whether manual annotation of the joint centers on 3D reconstructions could provide reliable recognition. Sixteen participants performed normal walking where 3D reconstructions were obtained continually. Segment lengths and kinematics from the extremities were manually extracted by eight expert observers. The results showed that all the participants were recognized, assuming the same expert annotated the data. Recognition based on data annotated by different experts was less reliable achieving 72.6% correct recognitions as some parameters were heavily affected by interobserver variability. This study verified that 3D reconstructions are feasible for forensic gait analysis as an improved alternative to conventional CCTV. However, further studies are needed to account for the use of different clothing, field conditions, etc.     

Three-dimensional cranio-facial reconstruction in forensic identification: latest progress and new tendencies in the 21st century

Three-dimensional (3D) cranio-facial reconstruction can be useful in the identification of an unknown body. The progress in computer science and the improvement of medical imaging technologies during recent years had significant repercussions on this domain. New facial soft tissue depth data for children and adults have been obtained using ultrasound, CT-scans and radiographies. New guidelines for facial feature properties such as nose projection, eye protrusion or mouth width, have been suggested, but also older theories and "rules of thumbs" have been critically evaluated based on digital technology. New fast, flexible and objective 3D reconstruction computer programs are in full development. The research on craniofacial reconstruction since the beginning of the 21st century is presented, highlighting computer-aided 3D facial reconstruction. Employing the newer technologies and permanently evaluating and (re)questioning the obtained results will hopefully lead to more accurate reconstructions.     

Getting in touch--3D printing in forensic imaging

With the increasing use of medical imaging in forensics, as well as the technological advances in rapid prototyping, we suggest combining these techniques to generate displays of forensic findings. We used computed tomography (CT), CT angiography, magnetic resonance imaging (MRI) and surface scanning with photogrammetry in conjunction with segmentation techniques to generate 3D polygon meshes. Based on these data sets, a 3D printer created colored models of the anatomical structures. Using this technique, we could create models of bone fractures, vessels, cardiac infarctions, ruptured organs as well as bitemark wounds. The final models are anatomically accurate, fully colored representations of bones, vessels and soft tissue, and they demonstrate radiologically visible pathologies. The models are more easily understood by laypersons than volume rendering or 2D reconstructions. Therefore, they are suitable for presentations in courtrooms and for educational purposes.     

Tests of one Brazilian facial reconstruction method using three soft tissue depth sets and familiar assessors

Facial reconstruction is a method that seeks to recreate a person's facial appearance from his/her skull. This technique can be the last resource used in a forensic investigation, when identification techniques such as DNA analysis, dental records, fingerprints and radiographic comparison cannot be used to identify a body or skeletal remains. To perform facial reconstruction, the data of facial soft tissue thickness are necessary. Scientific literature has described differences in the thickness of facial soft tissue between ethnic groups. There are different databases of soft tissue thickness published in the scientific literature. There are no literature records of facial reconstruction works carried out with data of soft tissues obtained from samples of Brazilian subjects. There are also no reports of digital forensic facial reconstruction performed in Brazil. There are two databases of soft tissue thickness published for the Brazilian population: one obtained from measurements performed in fresh cadavers (fresh cadavers' pattern), and another from measurements using magnetic resonance imaging (Magnetic Resonance pattern). This study aims to perform three different characterized digital forensic facial reconstructions (with hair, eyelashes and eyebrows) of a Brazilian subject (based on an international pattern and two Brazilian patterns for soft facial tissue thickness), and evaluate the digital forensic facial reconstructions comparing them to photos of the individual and other nine subjects. The DICOM data of the Computed Tomography (CT) donated by a volunteer were converted into stereolitography (STL) files and used for the creation of the digital facial reconstructions. Once the three reconstructions were performed, they were compared to photographs of the subject who had the face reconstructed and nine other subjects. Thirty examiners participated in this recognition process. The target subject was recognized by 26.67% of the examiners in the reconstruction performed with the Brazilian Magnetic Resonance Pattern, 23.33% in the reconstruction performed with the Brazilian Fresh Cadavers Pattern and 20.00% in the reconstruction performed with the International Pattern, in which the target-subject was the most recognized subject in the first two patterns. The rate of correct recognitions of the target subject indicate that the digital forensic facial reconstruction, conducted with parameters used in this study, may be a useful tool.     

Malnutrition, a rare form of child abuse: diagnostic criteria

Infantile malnutrition is often difficult to diagnose as it is rarely observed in industrialized countries. It may be associated with physical violence or occur in isolation. The essential clinical sign is height and weight retardation, but malnutrition also causes a variety of internal and bone lesions, which lead to neuropsychological sequelae and death. We report a rare case of death by malnutrition in a female child aged 6 1/2 months. The infant presented height and weight growth retardation and internal lesions related to prolonged protein-energy malnutrition (fat and muscle wasting, thymic atrophy, liver steatosis) resulting in a picture of marasmus or kwashiorkor. We detail the positive and negative criteria that established the diagnosis of abuse, whereas the parents had claimed a simple dietary error.     

Assessing age-related morphology of the pubic symphysis from digital images versus direct observation

The increasingly global role of a forensic anthropologist necessitates a proper means for archiving evidence for re-examination. Large quantities of evidence can be stored and be made readily accessible through digital imaging. This study focuses on age assessment from digital photographs for personal identity reconstructions. A comparison of 52 Suchey-Brooks scores assigned to digital images and actual bone revealed that age assessment from digital images can be completed with accuracy. Coefficients of concordance imply that there significant agreement between osteological assessment of aging criteria from digital images and direct observation-greater than random change alone (p < 0.05). However, assessments from images should be approached with caution since there are inherent limitations of the naked eye in identifying morphological changes in certain skeletal features, especially where older adults are concerned. Although there is no replacement for a hands-on physical assessment, a digital archive may facilitate the global needs of the forensic anthropologist.     

Haptics in forensics: The possibilities and advantages in using the haptic device for reconstruction approaches in forensic science

Non-invasive documentation methods such as surface scanning and radiological imaging are gaining in importance in the forensic field. These three-dimensional technologies provide digital 3D data, which are processed and handled in the computer. However, the sense of touch gets lost using the virtual approach. The haptic device enables the use of the sense of touch to handle and feel digital 3D data. The multifunctional application of a haptic device for forensic approaches is evaluated and illustrated in three different cases: the representation of bone fractures of the lower extremities, by traffic accidents, in a non-invasive manner; the comparison of bone injuries with the presumed injury-inflicting instrument; and in a gunshot case, the identification of the gun by the muzzle imprint, and the reconstruction of the holding position of the gun.The 3D models of the bones are generated from the Computed Tomography (CT) images. The 3D models of the exterior injuries, the injury-inflicting tools and the bone injuries, where a higher resolution is necessary, are created by the optical surface scan.The haptic device is used in combination with the software FreeForm Modelling Plus™ for touching the surface of the 3D models to feel the minute injuries and the surface of tools, to reposition displaced bone parts and to compare an injury-causing instrument with an injury.The repositioning of 3D models in a reconstruction is easier, faster and more precisely executed by means of using the sense of touch and with the user-friendly movement in the 3D space. For representation purposes, the fracture lines of bones are coloured. This work demonstrates that the haptic device is a suitable and efficient application in forensic science. The haptic device offers a new way in the handling of digital data in the virtual 3D space.     

A 25-year retrospective review of deaths due to pediatric neglect

Neglect, defined as the failure of a caregiver to adequately provide safety, food, clothing, shelter, education, protection, medical/dental care, and supervision for a child in his/her care, is a relatively uncommon but important cause of child mortality. A retrospective review of pediatric deaths (age 18 years or less) referred to the Medical University of South Carolina Forensic Pathology Office for autopsy over the past 25 years revealed 16 deaths due to some type of pediatric neglect. Cases were analyzed as to age, sex, race, cause and manner of death, autopsy findings, ancillary studies, past medical history, social/family history, and caregiver. Six cases of malnutrition/starvation and/or dehydration were identified, composing the most common cause of death in the neglect cases identified and the majority of the homicides due to neglect. Other deaths in which neglect contributed significantly included toxic ingestions (2 cases), hyper-/hypothermia (2 cases), unusual drowning/aspiration (4 cases), electrocution (1 case), and delayed/absent medical therapy (2 cases, including one of the previously mentioned ingestions). Of these additional cases, 7 were certified as accidental manner, 2 as natural, and 1 as a homicide. Cases which fell into a "gray zone" in which the appropriateness of invoking neglect was a matter of opinion or societal convention were excluded from the review; examples included conventional accidental drowning, choking on food or aspiration of foreign body, overlying/wedging during sleep, accidental hanging, and motor-vehicle traffic accidents (pedestrians, unrestrained passengers). The findings of this review reinforce the fact that malnutrition/starvation and dehydration compose the most common form of lethal pediatric neglect while highlighting less common forms of neglect and the difficulty of determining manner of death in cases in which neglect plays a more questionable role than in seemingly clear-cut malnutrition/starvation and dehydration cases. We demonstrate the typical victim and scenario that investigators will encounter in cases of fatal pediatric neglect, often a child under the age of 1 year who has been deprived of food and/or drink for some time, or an older, more independently mobile child who has not been adequately supervised. These children may or may not have a demonstrable prior history of maltreatment or (nonfatal) neglect, and review of medical records is an important part of the investigation. We additionally discuss key gross autopsy findings, appropriate specimen collection, helpful ancillary studies, microscopic findings of significance, potential mimickers of neglect, and other special considerations in cases of pediatric neglect.     

The juvenile death penalty and the Eighth Amendment

The present study investigated the Eighth Amendment tests of societal consensus and proportionality as applied to juvenile death penalties. A sample of former jurors (N=179) voted on whether to execute the defendant in a hypothetical case. Defendant's age (10, 15, 16, or 19) and level of remorse were varied. A large percentage of participants voted to execute the defendant in each condition, but the defendant's age and the participant's attitude toward juvenile culpability significantly predicted the likelihood of execution. Implications for the constitutionality of the juvenile death penalty and future research directions are discussed.     

An efficient technique for enhancing forensic capabilities of Ext2 file system

As electronic documents become more important and valuable in the modern era, attempts are invariably made to take undue-advantage by tampering with them. Tampering with the modification, access and creation date and time stamps (MAC DTS) of digital documents pose a great threat and proves to be a major handicap in digital forensic investigation. Authentic date and time stamps (ADTS) can provide crucial evidence in linking crime to criminal in cases of Computer Fraud and Cyber Crimes (CFCC) through reliable time lining of digital evidence. But the ease with which the MAC DTS of stored digital documents can be changed raises some serious questions about the integrity and admissibility of digital evidence, potentially leading to rejection of acquired digital evidence in the court of Law. MAC DTS procedures of popular operating systems are inherently flawed and were created only for the sake of convenience and not necessarily keeping in mind the security and digital forensic aspects. This paper explores these issues in the context of the Ext2 file system and also proposes one solution to tackle such issues for the scenario where systems have preinstalled plug-ins in the form of Loadable Kernel Modules, which provide the capability to preserve ADTS.     

A simple technique for imaging the human skeleton using a flatbed scanner

A simple technique for imaging the human skeleton with a flatbed scanner is presented using the auricular surface of the ilium as an example. A flatbed scanner with resolution capabilities of 600 dpi or greater allows for images of human bones. The auricular surface of the ilium was selected to demonstrate this technique as it is a fairly three-dimensional area that can be difficult to record photographically. Fifty left ilia of various ages at death from the Athens Collection were selected from which three observers (SCF, CE, and IM) scored the morphology of the auricular surface using a well-established aging method. Observations were taken of the dry bone, of digital photographs of the bone, and of scanned images of the bone, and in that sequence. Results indicate that scores of scanned images are equivalent or better than digital images of the same ilia. This technique allows for sharing data electronically with ease.     

Dietary health does affect histological age assessment: an evaluation of the Stout and Paine (1992) age estimation equation using secondary osteons from the rib

An age at death estimation equation that uses rib histological variables presented by Stout and Paine was used to evaluate a skeletal population of individuals with a known age at death and cause of death from either malnutrition or the niacin deficiency disease pellagra. The sample was comprised of 26 autopsied black South Africans. Histological analysis of mounted thin sections involved the microscopic measurement of cortical area and a count of the number of intact and fragmentary secondary osteons for the entire cross-section of the rib. Rib osteon population density values were then calculated for each case. It was found that this equation under-aged individuals on average by 29.2 years. Overall, secondary osteon size and Haversian canals tended to be larger than expected, while cortical bone area was less when compared with a control population. The implications of these findings are critical given that many of the skeletal remains examined by forensic anthropologists come from marginalized backgrounds, including malnutrition. This research suggests that measurements based on healthy cases may not be useful in an analysis of individuals with poor diet and health. It is argued that new standards for histological age assessment methods need to be created that account for variation in the health status of individuals examined by forensic anthropologists.     

Portable high‐resolution automated 3D imaging for footwear and tire impression capture

The forensic science community raised the need for improved evidence recognition, collection, and visualization analytical instrumentation for field and laboratory use. While the 3D optical techniques for imaging static objects have been extensively studied, there is still a major gap between current knowledge and collecting high‐quality footwear and tire impression evidence. Among optical means for 3D imaging, digital fringe projection (DFP) techniques reconstruct 3D shape from phase information, achieving camera‐pixel spatial resolution. This paper presents a high‐resolution 3D imaging technology using DFP techniques dedicated to footwear and tire impression capture. We developed fully automated software algorithms and a graphical user interface (GUI) that allow anyone without training to operate for high‐quality 3D data capture. We performed accuracy evaluations and comparisons comparing with the commercial high‐end 3D scanner and carried out qualitative tests for various impressions comparing with the current practices. Overall, our technology achieves similar levels of accuracy and resolution with a high‐end commercially available 3D scanner, while having the merits of being (1) more affordable; (2) much easier to operate; and (3) more robust. Compared with the current practice of casting, our technology demonstrates its superiority because it (1) is non‐destructive; (2) collects more evidence detail than casts, especially when an impression is fragile; (3) requires less time and money to collect each piece of evidence; and (4) results in a digital file that can easily be shared with other examiners.