Diagnostic accuracy of post-mortem computed tomography for fractures of the hyoid-larynx complex.

Post-mortem computed tomography (PMCT) is routinely used at many forensic institutions to guide the following autopsy and is especially useful for diagnosing fractures. This systematic review aims to investigate the sensitivity and specificity of a PMCT scan in fracture diagnosis of the hyoid-larynx complex (HLC) compared to traditional autopsy in cases involving traumatic neck injuries. We searched PubMed, SCOPUS and Web of Science and included papers with cases n ≥ 3 published between January 2000 and April 2023 reporting on PMCT and autopsy findings of fractures of the HLC. The search provided 259 results of which 10 were included. Overall sensitivity and specificity were 0.70 [0.59; 0.79] and 0.92 [0.80; 0.97] for hyoid bone fractures and 0.80 [0.62; 0.91] and 0.76 [0.63; 0.85] for the thyroid cartilage. The results show great variation, and a large range between studies. These results indicate that PMCT cannot replace autopsy in cases with HLC fractures. Future larger prospective studies are needed, examining fracture details, scan protocols and different slice thicknesses using uniform reporting.

Automated detection of fatal cerebral haemorrhage in postmortem CT data.

During the last years, the detection of different causes of death based on postmortem imaging findings became more and more relevant. Especially postmortem computed tomography (PMCT) as a non-invasive, relatively cheap, and fast technique is progressively used as an important imaging tool for supporting autopsies. Additionally, previous works showed that deep learning applications yielded robust results for in vivo medical imaging interpretation. In this work, we propose a pipeline to identify fatal cerebral haemorrhage on three-dimensional PMCT data. We retrospectively selected 81 PMCT cases from the database of our institute, whereby 36 cases suffered from a fatal cerebral haemorrhage as confirmed by autopsy. The remaining 45 cases were considered as neurologically healthy. Based on these datasets, six machine learning classifiers (k-nearest neighbour, Gaussian naive Bayes, logistic regression, decision tree, linear discriminant analysis, and support vector machine) were executed and two deep learning models, namely a convolutional neural network (CNN) and a densely connected convolutional network (DenseNet), were trained. For all algorithms, 80% of the data was randomly selected for training and 20% for validation purposes and a five-fold cross-validation was executed. The best-performing classification algorithm for fatal cerebral haemorrhage was the artificial neural network CNN, which resulted in an accuracy of 0.94 for all folds. In the future, artificial neural network algorithms may be applied by forensic pathologists as a helpful computer-assisted diagnostics tool supporting PMCT-based evaluation of cause of death.

Visualization of left common carotid artery injury by glass using postmortem virtual angioscopy.

A deceased man in his 50 s was found with his neck over a broken glass door frame, with blood around the body. A non-contrast postmortem computed tomography (PMCT) scan revealed subcutaneous hemorrhage, temporal bone fracture, and cerebral contusion. Also, wounds extending from the anterior to posterior neck and the presence of air in the cervical vessels suggested cervical vascular injury. A virtual angioscopy image reconstructed from PMCT angiography data revealed a ruptured left common carotid artery and allowed accurate measurement of the injury. This case demonstrates the effectiveness of postmortem virtual angioscopy for visualization and evaluation of vascular injuries, providing valuable insights for forensic investigation.

Lung densitometry in postmortem computed tomography - comparison across different fatal asphyxia groups.

Asphyxia as a cause of death poses a diagnostic challenge in forensic medicine due to both the diversity of underlying mechanisms, and lack of specific markers. Acute emphysema or acute alveolar dilation have long been debated as potential findings in these asphyxia cases. To further explore the supplementary findings in our forensic asphyxia cases, this study applied lung densitometry to pulmonary postmortem computed tomography (PMCT) data. Twenty asphyxia cases (including hanging (n = 9), manual strangulation (n = 4), ligature strangulation (n = 1), smothering (n = 3), and choking (n = 3)) and 21 matched control cases were analysed using lung densitometry parameters - specifically quantification of low attenuation areas (LAA) and the 15th percentile point of lung density (Perc15). Our data revealed statistically significantly higher lung % volume falling within LAA at -950HU (p = 0.04) and - 910HU (p = 0.043) in the asphyxia cases compared to matched controls. The Perc15 values observed were trending towards a lower attenuation corresponding to a lower density in the asphyxia group, although this result was not statistically significant (p = 0.13). A subgroup analysis highlighted potential differences within the asphyxia categories, notably, higher Perc15 values were observed in the choking cases. In conclusion the results from the study support the existing evidence of low pulmonary density as a potential finding in asphyxia cases and demonstrate the potential of applying lung densitometry on pulmonary postmortem computed tomography data.

Postmortem CT and autopsy findings in an elevator-related death: a case report.

Elevator-related fatalities and injuries are rarely discussed. Falls have been identified as the first cause of mortality in the majority of these accidents. Evidence suggests that many elevator accidents may be attributed to inadequate equipment maintenance or malfunctions of the devices. This study examines a case involving an elevator maintenance worker found within an elevator shaft, using postmortem computed tomography (PMCT) along with a full autopsy. The autopsy revealed that the cause of death was severe polytrauma resulting from dragging, compression, and crushing mechanisms, which resulted in a dislocated skull and multiple thoraco-abdominal injuries, including exposed organs and viscera. Detailed examination identified a cranio-encephalic crush, leading to a significant alteration in the physiognomy of the facial structures. Additionally, PMCT revealed complex spinal fractures, such as a Jefferson fracture and a complete Chance fracture at the D6 vertebra, accompanied by spinal deviation proximal to the fracture site. Autopsy findings corroborated these PMCT results. A multidisciplinary approach, including PMCT, is proposed as a strategic method for the comprehensive reconstruction of such accidents, facilitating the collection of extensive data.

Asbestos exposure determined 357 days after death through autopsy: a report of a multidisciplinary approach.

Asbestosis is an interstitial lung disease caused by the inhalation of asbestos fibers and poses a significant risk to individuals working in construction, shipping, mining, and related industries. In a forensic context, postmortem investigations are crucial for accurate diagnosis, for which the gold standard is the histopathological examination. This case report describes the autopsy and related investigations conducted on an 84-year-old man, nearly one year (357 days) after his death. After a post-mortem CT scan, an autoptic investigation was performed, followed by histopathological, immunohistochemical, and scanning electron microscopy examinations. The integration of the evidence from these examinations with previously available personal and clinical information conclusively confirmed the diagnosis of asbestosis. We demonstrated the efficacy and reliability of our diagnostic protocol in detecting asbestosis and asbestos fibers and excluding mesothelioma even in decomposed tissues. According to our findings autopsy remains the diagnostic gold standard in cases of suspected asbestosis within a forensic context, even 1 year after death, therefore it is always highly recommended, even in cases where the body has decomposed.

Suspension-associated dislocation of the jaw in hanging.

Hanging is a common type of death, and the role of the medical investigation of such deaths by a forensic pathologist not only requires the determination of the cause of death but providing information to assist in the determination of the manner of death. The forensic pathologist should be well versed in the spectrum of injuries known to be associated with neck compression, to document injuries known to be associated with hanging, but also to identify those that are inconsistent with self-inflicted hanging or that may suggest the involvement of a third party in the death. Comprehensive identification and correct interpretation of external and internal injury are crucial for the appropriate degree of police and coroner/medical examiner investigation. We present two cases of deaths believed to be caused by self-inflicted hanging that were observed to have unexpected unilateral dislocation of the temporomandibular joint identified on routine post-mortem computed tomography, without any evidence of involvement of a third party. This injury was unexplained and had not been previously observed at our Forensic Institute nor was it identified after a review of the published biomedical research literature. Issues regarding the cause of this abnormality, possible mechanisms, and the medicolegal significance of this finding will be discussed.

Skeletal and dental age estimation via postmortem computed tomography in Polish subadults group.

This article is a retrospective analysis of postmortem computed tomography scans of ossification stages of the anterior and posterior intra-occipital sutures, the anterior arch of the atlas, and the neurocentral junction of the axis. We also analyzed the development of secondary ossification centers in the proximal humeral, femoral, and tibial epiphyses, and the distal femoral and tibial epiphyses. Additionally, the development of primary ossification centers in the wrist and metacarpals, and maxillary and mandibular deciduous tooth maturation. A total of 58 cadavers (35 males, 23 females), whose age ranged from 3rd month of pregnancy to 14 years, were analyzed. The results of this study show that analysis of synchondrosis closure, primary, and secondary ossification center development and deciduous tooth changes are a good tool for age estimation in subadults group (fetuses, newborns, infants, and children). The results of the study in a Polish population are consistent with those reported by other authors.

How low can we go? CT dose reduction in the assessment of the medial clavicular epiphysis in forensic age estimation: a prospective postmortem CT study.

BACKGROUND: Projection radiography and, more recently, computed tomography (CT) play an important role in forensic age estimation. Both in terms of general criminal responsibility and government regulations concerning refugee care, it is important to differentiate correctly between youths and adults. A disadvantage of age estimation in CT is the ionizing radiation exposure. PURPOSE: To investigate how far the CT dose can be reduced without losing diagnostic confidence in assessing the different stages of ossification of the medial clavicle. MATERIAL AND METHODS: We prospectively scanned 25 postmortem cases with a fixed parameters protocol (FPP) and a care dose modulation protocol (CDMP) for different scan parameters. Two radiologists assessed the diagnostic image quality using a 5-point Likert scale. Inter-reader agreement was evaluated with Cohen's kappa. Differences in doses between FPP and CDMP were assessed with the one-tailed t-test. RESULTS: The best combination of diagnostic image quality and lowest radiation dose was obtained using a CDMP with 100 kV and 40 mAs and an FPP with 100 kV and 30 mAs. Doses for 120 kV were significantly higher (one-tailed P < 0.001). The diagnostic image quality for 80 kV was insufficient overall. DISCUSSION: Our results confirm that CT imaging at 100 kV allows a sufficient image quality that is diagnostic for age estimation in the ossification of the medial clavicle.

Lateralized hypostasis of the head on post mortem CT (PMCT) scanning of decomposed bodies-a marker for terminal position.

Post-mortem CT (PMCT) scanning was performed on the bodies of two decomposed adult males who had died of natural causes. The bodies both showed changes of marked decomposition with a prominent swelling of tissues on one side of the head compared to the other. A review of police statements confirmed that this matched the positions of the bodies when they were found. Thus, post-mortem hypostasis of putrefactive fluids correlated in both cases with the positions that the bodies had been in when first located. This may be a simple way of identifying or confirming the positions of decomposed bodies after death. It may also assist in indicating whether a body has been moved after putrefactive fluid hypostasis has developed.

Acute subdural hematoma caused by rupture of a mycotic aneurysm due to meningitis associated with infectious endocarditis: comparison of autopsy findings with postmortem computed tomography.

Forensic pathologists often encounter cases of acute subdural hematoma (SDH) due to trauma, whereas those attributable to endogenous causes are rare. Here, we report a case of the latter type in a 42-year-old man who was found dead at home after several months of fever and malaise. Postmortem computed tomography (PMCT) and autopsy were undertaken to clarify the cause of death. PMCT images revealed a fatal SDH and a localized hyper-density area in the right parietal lobe; macroscopic and microscopic examinations revealed SDH due to rupture of a mycotic aneurysm (MA) associated with meningitis. The PMCT images also indicated thickening and calcification of the mitral valve, while autopsy demonstrated infective endocarditis (IE). In addition, PMCT demonstrated a low-density area in the spleen, which was shown to be a splenic abscess at autopsy. PMCT also demonstrated tooth cavities. Based on the findings of autopsy, the cause of death was considered to be SDH due to rupture of the MA resulting from meningitis with IE and splenic abscess. Although PMCT was unable to clarify the significance of any individual feature, a retrospective review of the PMCT images might have suggested IE, bacteremia, or ruptured MA leading to SDH. This case suggests that, instead of interpreting individual features demonstrated on PMCT images, integrated interpretation of overall PMCT findings might provide clues for identifying causes of death, despite the fact that PMCT lacks diagnostic accuracy for infectious diseases such as IE and meningitis.

Extensive subcutaneous needle fragment retention due to injecting drug use.

Deaths in those with a history of injecting drug use commonly come to the attention of forensic pathologists, and therefore, one must have knowledge of possible findings and hazards of performing autopsies in these cases. This case demonstrates the finding of extensive retained broken needles in the subcutis of the arms and femoral region in a man with a long history of injecting drug use. While few or single broken needles are not uncommonly encountered, the multiplicity of needles in this case is noteworthy. We have demonstrated the findings both radiologically with PMCT and by conventional autopsy.

Marine mimicry is afoot.

It is a relatively common occurrence for forensic pathologists and anthropologists to be presented with what are believed to be human remains as part of their day-to-day practice. Despite this, the literature pertaining to such challenges is not extensive, and much knowledge of this is largely based on experience. As such, we present a case of what appeared to be a severed foot located on a beach, which examination revealed was a marine animal known as a sea squirt (ascidian). While marine scientists have been aware of such mimicry, to our knowledge, this has not been previously described in the forensic pathology literature. The external examination and post-mortem CT scan revealed the nonhuman nature of the remains, and an imminent police investigation was prevented, saving time and resources. Nonhuman remains may include animals and inorganic objects, and their discovery may invoke anxiety in the finder. A timely forensic pathology or anthropology examination will assist in alleviating such concern. Forensic pathologists and anthropologists should be prepared to face a variety of presented remains and objects.

Sensitivity and specificity of post-mortem computed tomography in skull fracture detection-a systematic review and meta-analysis.

Post-mortem computed tomography (PMCT) has been increasingly used as routine examination in forensic pathology. No recent review of the growing number of papers on the ability of PMCT to detect skull fracture exists, and original papers report sensitivities from 0.85 to 1.00. This systematic review (PROSPERO: CRD42021233264) aims to provide a meta-analysis of sensitivity and specificity of PMCT in skull fracture detection. We searched PubMed, MEDLINE and Embase for papers published between January 2000 and August 2021 reporting raw numbers, sensitivity and specificity or Abbreviated Injury Score for PMCT compared to autopsy. Papers without both PMCT and autopsy, no separate reporting of the neuro-cranium, exclusively on children, sharp trauma, gunshot or natural death as well as case reports and reviews were excluded. Two authors independently performed inclusion, bias assessment and data extraction. QUADAS-2 was used for bias assessment and a random effects models used for meta-analysis. From 4.284 hits, 18 studies were eligible and 13 included in the meta-analysis for a total of 1538 cases. All deceased were scanned on multi-slice scanners with comparable parameters. Images were evaluated by radiologists or pathologists. Intra- and inter-observer analyses were rarely reported. In summary, sensitivity of PMCT for detection of fractures in the skull base was 0.87 [0.80; 0.92] with specificity 0.96 [0.90; 0.98], and sensitivity for the vault was 0.89 [0.80; 0.94] with specificity 0.96 [0.91; 0.98]. The mixed samples are a limitation of the review.

Comparison of findings identified at traditional invasive autopsy and postmortem computed tomography in suicidal hangings.

Cases of suicidal hanging are a common death referred for medico-legal autopsy throughout the world. Although some advocate using postmortem computed tomography (PMCT) without traditional invasive autopsy (TIA) to investigate such deaths, others reject this approach. There is currently limited evidence to guide practice. In this context, the TIA reports and PMCT images of 50 cases of suspected suicidal hanging during an 11-month period were reviewed. The reviewers were blinded to the findings of the other modality. A Cohen's Kappa coefficient (K) was calculated to assess agreement between TIA and PMCT across a range of pertinent findings. This analysis demonstrated perfect agreement for identification of a ligature (K = 1.00) and a strong level of agreement for identification of a ligature suspension point (K = 0.832) but only a minimal level of agreement for overall ligature mark (K = 0.223). PMCT demonstrated a weak level of agreement for fractures of hyoid bone (K = 0.555) and thyroid cartilage (K = 0.538). Three probable fractures not identified at TIA were identified on PMCT. TIA was shown to be superior in the identification of intramuscular and laryngeal fracture-related haemorrhage/bruising whereas PMCT was superior to TIA in identifying body gas deposition. There was overall good correlation between the natural disease and trauma identified elsewhere in the body during the TIA and PMCT. The study demonstrates that PMCT can assist the investigation of suspected suicidal hangings. However, the accuracy of many findings is limited, and if it is used as an alternative to the TIA, potentially pertinent findings, such as fractures of the laryngeal cartilages, could be missed.

Postmortem computed tomography differentiation between intraperitoneal decomposition gas and pneumoperitoneum.

PURPOSE: The aim of this study is to investigate the ability of postmortem computed tomography (PMCT) to distinguish intraperitoneal decomposition gas from pneumoperitoneum due to intestinal perforation. METHODS: This retrospective study investigated the factors affecting intraperitoneal gas in two groups of 14 decedents as detected by postmortem CT performed in the Department of Legal Medicine of Hamburg University. The first group died with a cause of death associated with intestinal perforation, and the second group with other different natural causes of death. These factors include postmortem interval, gas volume, gas distribution, radiology alteration index (RAI), and pneumoperitoneum-associated pathology. RESULTS: The findings of this study showed the appearance of specific gas distribution patterns and a significant increase in gas volumes in the cases of intestinal perforation. Moreover, postmortem interval and the pneumoperitoneum-associated pathology could help distinguish postmortem-generated gas from pneumoperitoneum. CONCLUSION: Based on the findings of this study, we propose that these findings can improve the proper detection of intestinal perforation cases in the future.

Thermal bone injuries: postmortem computed tomography findings in 25 cases.

INTRODUCTION: Fire death investigations attempt to determine whether a subject was alive or dead before the fire started. Therefore, it is essential to assess if the bone damage is traumatic or the result of exposure to heat. This observational study aims to expose the specific CT semiology of thermal bone lesions to allow the forensic radiologist to identify and distinguish them from traumatic lesions that would have preceded death. MATERIALS AND METHODS: We retrospectively reviewed the CT findings of 25 bodies with thermal bone lesions for which a postmortem computed tomography (PMCT) was performed prior to an autopsy. Imaging findings were correlated to the autopsy data to identify the specific features of thermal bone lesions. RESULTS: Specific signs of thermal injuries to bone were identified on PMCT on all deceased cases. Thermal damages predominated in areas directly exposed to flames (rib cage, distal extremities) with less soft tissue coverage ("soft tissue shielding"). The mottled appearance of bone marrow was a constant sign of burned bones. Heat fractures such as trans-diploic fractures of flat bones and beveled ("flute-mouthpiece") fractures of extremities seemed specifically related to thermal mechanism. In addition, we provided a better description of superficial cortical fissures of flat bones ("ancient Chinese porcelain") and observed a "stair step" fracture of a long bone until now undescribed in radiological literature. CONCLUSION: Thermal bone lesions have specific CT findings, different on several points from traumatic injuries. Their knowledge is essential for radiologists and forensic physicians to provide an accurate report of injury and conclusions.

RiFNet: Automated rib fracture detection in postmortem computed tomography.

Imaging techniques are widely used for medical diagnostics. In some cases, a lack of medical practitioners who can manually analyze the images can lead to a bottleneck. Consequently, we developed a custom-made convolutional neural network (RiFNet = Rib Fracture Network) that can detect rib fractures in postmortem computed tomography. In a retrospective cohort study, we retrieved PMCT data from 195 postmortem cases with rib fractures from July 2017 to April 2018 from our database. The computed tomography data were prepared using a plugin in the commercial imaging software Syngo.via whereby the rib cage was unfolded on a single-in-plane image reformation. Out of the 195 cases, a total of 585 images were extracted and divided into two groups labeled "with" and "without" fractures. These two groups were subsequently divided into training, validation, and test datasets to assess the performance of RiFNet. In addition, we explored the possibility of applying transfer learning techniques on our dataset by choosing two independent noncommercial off-the-shelf convolutional neural network architectures (ResNet50 V2 and Inception V3) and compared the performances of those two with RiFNet. When using pre-trained convolutional neural networks, we achieved an F1 score of 0.64 with Inception V3 and an F1 score of 0.61 with ResNet50 V2. We obtained an average F1 score of 0.91 ± 0.04 with RiFNet. RiFNet is efficient in detecting rib fractures on postmortem computed tomography. Transfer learning techniques are not necessarily well adapted to make classifications in postmortem computed tomography.

Lethal hemorrhage from iliac vein rupture complicating inferior vena cava thrombosis demonstrated by post-mortem CT angiography.

Spontaneous iliac vein rupture is a rare cause of retroperitoneal hemorrhage that may present to the forensic pathologist. It has been reported in association with venous thrombosis, anatomical variants such as May-Thurner syndrome, and as a complication of a long-term indwelling IVC filter. It has a female predominance and most often occurs due to rupture of the left iliac vein. This is the first report of the use of post-mortem computed tomography (PMCT) and post-mortem computed tomography angiography (PMCTA) as an adjunct to a conventional autopsy to diagnose rupture of the left iliac vein causing retroperitoneal hemorrhage arising as a complication of an inferior vena cava (IVC) thrombus. We discuss the use of PMCTA as a useful tool in the diagnosis of vascular injury and how it can be used to assist the forensic pathologist. The use of PMCT with PMCTA is an invaluable adjunct to conventional autopsy to diagnose the site of vascular rupture.

Scopolamine fatal outcome in an inmate after buscopan® smoking.

Scopolamine is an alkaloid which acts as competitive antagonists to acetylcholine at central and peripheral muscarinic receptors. We report the case of a 41-year-old male convict with a 27-year history of cannabis abuse who suddenly died in the bed of his cell after having smoked buscopan® tablets. Since both abuse of substances and recent physical assaults had been reported, we opted for a comprehensive approach (post-mortem computed tomography CT (PMCT), full forensic autopsy, and toxicology testing) to determine which was the cause of the death. Virtopsy found significant cerebral edema and lungs edema that were confirmed at the autopsy and at the histopathological examination. Scopolamine was detected in peripheral blood at the toxic concentration of 14 ng/mL in blood and at 263 ng/mL in urine, and scopolamine butyl bromide at 17 ng/mL in blood and 90 ng/mL in urine. Quetiapine, mirtazapine, lorazepam, diazepam, and metabolites and valproate were also detected (at therapeutic concentrations). Inmates, especially when they have a history of drug abuse, are at risk to use any substance they can find for recreational purposes. In prisons, active surveillance on the management and assumption of prescribed drugs could avoid fatal acute intoxication.