Forensic Imaging最新文献

Introduction

Ventilated PMCT (VPMCT) has been reported to provide better quality of pulmonary structures in PMCT in adults and children. However, there are no consensus regarding optimal inflation pressure, and the practical use of VPMCT is still limited by cost of ventilation equipment. Here, we describe a simple and cost-efficient inflation-device for VPMCT and investigate optimal inflation pressure.

Aim

To elucidate the effect of different ventilation pressures on total lung volume and the volume of ground glass opacities (GGO), air-filled tissue, consolidations, and bronchi in VPMCT.

Materials and method

A precise inflation device was assembled using standard components: a back-pressure regulator, a water manometer and silicone tubing. Each case had PMCT performed at 0, 10, 20, 30 and 40 cmH₂O pressure. Volumes were measured using stereology.

Results

14 cases were enrolled in the study. The total lung volume increased significantly by 3612 mL (median) from 0 to 30 cmH₂O (p = 0.001). The volume of consolidations was significantly reduced by 455.86 mL (median) between 0 and 30 cmH₂O (p = 0.001). A significant reduction of GGO-volume of 133 mL (median) was observed at the pressure interval 30–40 cmH₂O (p = 0.031), but not at lower pressures.

Conclusion

The constructed inflation device allowed precise and reproducible inflation of the lungs in deceased humans. We found a maximum effect of inflation at 30 cmH₂O. At further inflation pressure, only the volume of GGOs decreased , but the effect was minor. For mimicking an in vivo breath-hold scan in PMCT we recommend inflation pressure of 30 cmH₂O.

Background

The value of post-mortem computed tomography (PMCT) in trauma victims is well established. In this review the diagnostic accuracy and value of PMCT will be investigated specifically for fire related deaths, which has yet to be fully investigated.

Methods

PRISMA guidelines informed this systematic review. A total of ten databases were searched in December 2020. All articles exploring the use of PMCT and autopsy to investigate fire related deaths in adults were deemed eligible for inclusion, and were reviewed by two independent researchers. The QUADAS-2 tool was used to assess the quality of these papers.

Results

Seven studies were selected, containing a total of 110 burns victims. PMCT was superior in identifying fractures, and is particularly accurate with regards to fractures and injuries of the skull, facial bones, neck and extremities. However, PMCT fared poorly in identifying signs of vitality during a fire compared to autopsy. Toxicological examinations to assess carbon monoxide levels were often still required to make a conclusive diagnosis of fire as the cause of death.

Conclusions

Despite the heterogeneity of the methodologies’ reviewed, it is clear that PMCT is an extremely powerful visualisation tool with great potential for documentation and examination in forensic cases. The limitations of PMCT mean that it can not fully replace autopsy in these cases, but if autopsy is not available PMCT, in combination with a toxicology and histology examination, can identify the cause of death to a high degree of certainty.

Background/Objective

In forensic anthropology, the biological profile is based on human variation and can help in the process of personal identification. In order to better understand shape variation of the mental region, this study analyzed the influence of population affinity and sex on the menton in adult black and white South Africans, using geometric morphometric methods (GMM).

Materials and Methods

We used cone-beam computed tomography (CBCT) scans of 291 adult dental patients with dentition patterns up to Eichner Index B3, retrospectively collected from the Oral and Dental Hospital, University of Pretoria. We placed eleven standard craniometric landmarks on the menton, mandible, and maxilla of three-dimensional (3D) reconstructions by automatic landmarking and analyzed them by applying GMM. In addition, a subtle shape matrix of seven landmarks was created for a focused analysis of the menton only. Finally, we tested the reproducibility of the landmarks placement with a dispersion analysis.

Results

The landmarks used in this study were reproducible, with an overall dispersion of less than 1 mm. Population affinity significantly influenced menton shape, with P-values = 0.001 in the complete sample and within the sex groups. Differences between sexes for these seven landmarks were also statistically significant (P-values between 0.001 to 0.003) in the complete sample, but not within population groups in isolation. The accuracy for estimation of population affinity by discriminant function analysis was 86.9%.

Conclusion

The use of automatic landmarking improved landmark reproducibility. Population affinity and sexual dimorphism significantly influenced menton shape. However, shape analysis, including all eleven landmarks, was not significantly influenced by sex. This study supports further research focusing on the facial approximations for forensic identification in South Africa.

Objective

To assess the values of the antegonial angle on panoramic radiographs and assess their role in age and sex determination.

Materials & Method

A study was carried out on 400 selected panoramic radiographs (200 males and 200 females) in the age group of 20 to 70 years. The antegonial angle was evaluated for its predictability in sex determination and age assessment. Required Statistical analysis was done.

Results

There was a significant difference in mean values of antegonial angle between males and females.

Conclusion

The antegonial region values are influenced by sex and have the potential to be used as a forensic tool in sex determination but not for age estimation.

Background

Three-dimensional (3D) documentation of crime and crash scenes is common practice during forensic and medicolegal investigations. Such documentation at a scene is usually carried out by specially trained personnel using various 3D imaging devices and methods, such as terrestrial laser scanners. Unfortunately, this causes the implementation of 3D documentation at the scenes to be expensive and not readily accessible. In 2020, Apple introduced a light detection and ranging (LiDAR) sensor into their high-end mobile devices. In 2022, Recon-3D, an iOS application (app), was launched. This app turns an iPhone or iPad into a 3D scanner and is specifically targeted at crime and crash scene applications.

Objectives

The aim of this study was to test the Recon-3D app based on exemplary scenarios to see whether this technology is generally applicable to document crime or crash scenes.

Materials and Methods

An iPhone 13 Pro in combination with the Recon-3D app was used to document two indoor scenarios, a mock-up crime scene and a garage, as well as an outdoor scenario of a parked car. Each scenario was documented multiple times.

Results

On average, data acquisition for one scene took less than 2 min. Known distances within the scenes were measured with a mean absolute error of 0.22 cm and a standard deviation of 0.18 cm.

Conclusion

The imaging workflow was simple and quick, enabling any person to perform 3D documentation at a crime or crash scene. Overall, Recon-3D appeared to be a useful application for forensic investigators.

Background

This study presents the incidental finding of Paget's disease within archaeological skeletal remains using radiography. The remains of a late medieval (14^th-15^th century AD) adult male were excavated in 2017 from St Albans Monks’ Graveyard, Hertfordshire, United Kingdom. Upon visual inspection the skeleton exhibited widespread changes suggestive of Paget's disease which prompted the radiographic investigation. The resultant imaging demonstrated an expanded bone and coarse trabecular patterns characteristic of the pathology.

Discussion

Forensic radiography provides valuable information for the reconstruction of biological profiles of the deceased for victim identification. Characteristic medical conditions such as Paget's disease aid identification by excluding unaffected persons, as the pathology exhibits a higher prevalence among British white males of advanced age. This example, although archaeological in origin, illustrates how data available from human skeletal remains can be leveraged through radiographic imaging to glean biographical information which might otherwise be unavailable. In the presence of fragmentary skeletal remains, and the absence of DNA profiling, pathologies with characteristic radiographic appearances could be of forensic significance.

Conclusion

This example demonstrates the radiographic appearances of Paget's disease on fragmentary skeletal remains which may aid victim identification efforts. Consideration must be given to the limitations of Paget's disease including anthropological estimations and the potential for alternative diagnoses. Lastly, radiography may offer an accurate, permanent record of the deceased as secondary evidence for identification efforts.

The herniation of lungs into the deep neck space should be considered as a particular sign of possible crush injury or severe chest compression, particularly in presence of other injuries indicating that possibility such as multiple rib fractures. This report details a case of severe chest compression in a pedestrian by a heavily loaded truck. Generally, cervical lung herniation is relatively rare; most instances of lung herniation tend to be thoracic (not diaphragmatic or cervical).

Odontology is one of the primary means for human identification. As common components of dental practice, intraoral radiographs represent an important source of antemortem (AM) data. Interpretation of these radiographs, however, may vary between forensic odontologists. The aim of this study was to investigate experts’ opinions on the interpretation of dental identifiers from intraoral radiographs. A web-based survey was distributed to international forensic odontologists. The survey included simulated cases of human identification and questions related to the use of intraoral radiographs in dental identification. Each case required the visual radiographic comparison of one AM and one postmortem (PM) intraoral radiograph. Further questions were related to the importance of different parameters that can be examined through intraoral radiographs, such as morphological, therapeutic, and pathological features; while final questions were asked about the methods used for comparative dental analysis. The survey was answered by 57 forensic odontologists across the world. The simulated case that involved therapeutic features (dental restorations) was positively identified by 56 participants (98%), while the case without therapeutic identifiers was identified only by 14 participants (24%). Almost half (54%) of the participants mentioned therapeutic features as the best (when available) for comparative human identification, followed by morphological features. The use of comparative methods for radiographic analysis was mentioned by 18 participants (32%). Intraoral radiographs enabled the analysis of dental and non-dental features – that can be therapeutic, morphological, and pathological. Specifically, therapeutic features allow a more straightforward comparison, while morphological comparisons require detailed visualization, and knowledge of anatomic structures and their variations.

Objectives

To review the recent facial soft tissue thickness literature (2018-22) to determine if authors are currently adhering to standardised cephalometric landmarks and nomenclature, thereby supporting best scientific practices.

Materials and Methods

Facial soft tissue thickness (FSTT) studies published between 2018 – 2022 were identified using Google Scholar with the search phrase: facial AND soft tissue AND thickness AND craniofacial AND identification AND/OR forensic. Twenty-three resulting papers were reviewed for their landmark content.

Results

Across the 23 studies, a mean of 12 common landmarks were measured from a maximum set of 36 (mean = 19). Twenty of 23 papers used at least one non-standardised or novel landmark. This included studies that awarded standard landmark names, but whose definition(s) diverged from standards. Other novelties included non-standard use of landmark abbreviations (e.g., description of only one landmark for what is in fact cephalometric pairs of landmarks), confusion of proximally located landmarks with one another, departure from pre-existing technical terminology to imprecise lay vocabulary, and entirely new landmark formulations.

Conclusions

Despite prior calls to the importance of standardisation in FSTT research, recent literature continues to exhibit broad departures from established standards. While novel landmarks provide highly valuable information, in any study, they should supplement a minimum set of standard landmarks so that cross-comparisons between studies using identically collected measurements are possible. Future FSTT research should award greater attention to including and meeting established FSTT cephalometric standards.

Forensic imaging studies were used to supplement the postmortem examination of a poodle-type dog that died of an unknown cause in an animal crime investigation. The carcass was powdered and the neck was twisted to the left. At the death scene, the police felt crepitation while moving the carcass to the autopsy room. They wondered whether the ribs and cervical bones of the carcass had been broken. Conventional X-rays revealed air pockets along the trachea and also an abundance of air in the subcutaneous tissue and body cavities. Three-dimensional volume-rendered images created from postmortem computed tomography confirmed that the hyoid bone, cervical vertebrae, and ribs were all intact. The findings during the autopsy were focally extensive intradermal and intramuscular hemorrhages and bruises on the right side of the body, tracheal rupture, and substantial brain congestion and edema. The results of the imaging and autopsy findings referred to asphyxiation and hypoxic ischemic stroke in the manner of death caused by blunt force trauma to the neck. During the police inquiry, the accused confessed to strangling the dog with her bare hands.