Detection of butterfly fractures of long bones through multi-slice computed tomography and micro-computed tomography

Motor-vehicle accidents often result in lower limb injuries with biosseous fractures. The present study aimed at comparing multi-slice computed tomography (MS-CT), micro-computed tomography (micro-CT) and external fractography for the analyses of experimentally produced biosseus leg fractures. Briefly, 48 human legs amputated for medical reasons were defleshed and then experimentally fractured using a 3-point dynamic bending model (70,6 J of impact energy at the middle of the anterior surface of the tibia) producing 38 biosseous and 10 mono-osseous fractures with a total of 86 fractured bones. External fractography detected 63 (73,2%) "butterfly" fractures (24 (27,9%) complete and 39 (45,3%) incomplete), 14 (16,3%) "oblique" fractures, 6 (7,0%) "comminuted" fractures and 3 (3,5%) "transverse" fractures. Forty-three (43) of the 48 included legs displayed at least one butterfly fracture located at the tibia or fibula. MS-CT correctly detected and classified 16 complete and 20 incomplete butterfly fractures, failing to properly classify 27 fractures; 19 of these misclassifications led to an interpretative error on the trauma direction (i.e., 16 incomplete butterfly fractures classified as oblique fractures and 3 incomplete butterfly fractures classified as transverse). Micro-CT correctly detected and classified 22 complete and 37 incomplete butterfly fractures, failing to properly classify 4 fractures; two of these misclassifications led to an interpretative error on the trauma direction (i.e., two incomplete butterfly fractures classified as oblique fractures). Although further studies evaluating a wider number of fractures and fracture patterns are required to drive any definitive conclusions, this preliminary experimental investigation showed that MS-CT and micro-CT represent useful tools for reconstructing the morphology of leg fractures and could be crucial for trauma analysis in the forensic context. MS-CT could be used as a screening tool, micro-CT as second level analysis and external/internal fractography as third level, confirmatory analysis.

Homicide, suicide, or accident? Complex differential diagnosis. A case series

Distinguishing between homicides, suicides, and accidental deaths remains a challenging task. The examination of actual cases, which involve a multitude of variables, significantly contributes to our understanding of these matters. In this context, we present three distinct cases that required the involvement of various specialists to conduct a thorough analysis of the manner of death. In the first case, the integration of on-site inspection, autopsy, radiological, and kinematic data enabled the identification of a homicidal death. In the second case, the combination of circumstantial evidence, autopsy findings, toxicological analysis, and meteorological data revealed an atypical accidental death resulting from an attempted suicide. In the third case, radiological findings, supplemented with criteria from forensic science, indicated an accidental manner of death. In all reported cases, a multidisciplinary approach played a pivotal role in the differential diagnosis of the manner of death.

Under-reporting of forensic findings: craniocervical emergency imaging in cases of survived hanging

To determine the diagnostic bias between clinical and forensic radiology in cases of nonfatal hanging and determine and describe typical underreported imaging findings. In a retrospective, single-center study, all patients admitted for attempted suicide with near-hanging or fatal hanging between January 2008 and December 2020 who received CT or MRI of head and neck were reviewed and missed findings in the original report were documented. A binary regression with disagreement as dependent variable was fitted for the imaging modality, fatality, age, and sex. A total of 123 hanging incidents were retrospectively analyzed. The vast majority (n = 108; 87.8%) had attempted suicide with a nonfatal outcome. Fatal outcome occurred in 15 (12.0%). The extra- and intracranial injuries documented on CT and MRI scans were laryngeal (n = 8; 6.5%), soft tissue (n = 42; 34.1%), and vascular injuries (n = 1; 0.8%). Intracranial pathology was evident on 18 (14.6%) scans. Disagreement occurred in 36 (29.3%) cases and represented 52 (69.2%) of all cases with a radiological finding. Disagreement was strongly associated with fatality (OR: 2.7-44.9.4, p = 0.0012). In most cases, nonfatal hangings cause no or only minor injuries. Fatal cases are associated with a greater probability of missed minor imaging findings. This suggests that findings deemed clinically irrelevant are probably not reported in such severe emergency cases. This association indicates that minor abnormalities are underreported when major pathologies are evident on imaging in victims of strangulation.

Fatal gastric volvulus: forensic pathology considerations and postmortem CT findings

Gastric volvulus is a rare cause of gastric obstruction, due to the rotation of the stomach by more than 180°. It is a rare but life-threatening medical emergency that is considered difficult to diagnose at the initial clinical presentation. Forensic pathologists may be presented with gastric volvulus in several ways, for instance, as a cause of sudden and unexpected death or in the context of suspected clinical errors. The post-mortem examination of gastric volvulus may be challenging, due to the specific technical issues it presents and the various mechanisms by which volvulus may cause death. We therefore present five cases of gastric volvulus that in combination represent almost the entire spectrum of presentations and post-mortem findings, to discuss how gastric volvulus may come to the attention of a forensic pathologist, the approach and findings at post-mortem examination (including post-mortem CT), and the variety of mechanisms by which gastric volvulus may result in death.

Examination of postmortem changes in the lungs, trachea, and bronchi in a rat model imaged with small-animal computed tomography

Objectives

As less autopsies are performed, the need for postmortem computed tomography (PMCT) as an alternative is increasing. It is important to know how postmortem changes over time are reflected on CT, in order to improve the diagnostic capability of PMCT and replace forensic pathology evaluations such as time of death estimation.

Methods

In this study, we examined temporal changes on postmortem chest CT images of a rat model. After acquiring antemortem images under isoflurane inhalation anesthesia, the rats were euthanized with a rapid intravenous injection of anesthetics. From immediately after death to 48 hours postmortem, chest images were acquired using small-animal CT. The 3D images were then evaluated on a workstation to measure the antemortem and postmortem air content in the lungs, trachea, and bronchi over time.

Results

The air content in the lungs decreased, but the air content of the trachea and bronchi temporarily increased 1-12 hours postmortem, then decreased at 48 hours postmortem. Therefore, the measurement of trachea and bronchi volumes on PMCT could be an objective way to estimate the time of death.

Conclusions

While the air content of the lungs decreased, the volume of the trachea and bronchi temporarily increased after death, indicating the potential to use such measurements to estimate time of death.

Characterization of subdural collections in initial neuroimaging of abusive head trauma: Implications for forensic age diagnostics and clinical decision-making

PURPOSE

Subdural collections (SDCs) represent a key finding in abusive head trauma (AHT), a serious form of child physical abuse. Common SDC entities in this context are subdural hematoma (SDH), subdural hygroma (SDHy), subdural hematohygroma (SDHHy), and chronic subdural hematoma (cSDH). The present study examines the prevalence of the different SDC entities and investigates the influence of the SDC diagnosis on the forensic age estimation of the injury.

METHODS

In this retrospective multi-center study from three German university hospitals of a 10-year period, the initial neuroimaging material (CT or MRI) of 56 children (36 males, 20 females; age median 3.9 months) with medico-legally well-documented AHT was analyzed. SDCs were characterized by determining presence, location, extension, and visual appearance, by assigning to one of the five entities, and by categorizing with three different classification systems, one of which represents a novel system based on focality and Mixed Appearance Pattern and especially developed for children with AHT. The data were correlated with demographic and clinical data. By means of court files, AHT cases were also sub-divided into confession (n = 14) and non-confession cases (n = 42) and then compared.

RESULTS

Most cases showed a multifocal presence of SDCs (96.4%) and the presence of a Mixed Appearance Pattern (82.1%). The most common SDC entity was the heterogeneous variant of the SDHHy (66.1%). The cSDH occurred infrequently only (3.6%). Our novel classification system illustrates that unifocal SDCs rarely occur in AHT, and that more complex SDC patterns are common. In nearly all cases (94.6%), additional signs of recently caused brain injury were present beside the SDCs. Comparison between confession and non-confession groups did not reveal any significant differences, indicating that the diagnostic criteria of AHT are robust.

CONCLUSIONS

Although precise dating of SDCs based on initial neuroimaging alone remains unrealistic, the exact diagnosis of the SDC entity provide an important basis for differentiation between acute trauma and chronic post-traumatic state. Therefore, especially the confirmation or exclusion of subdural neomembranes, that define the cSDH, should be considered indispensable.

The distal femoral epiphysis in forensic age diagnostics: studies on the evaluation of the ossification process by means of T1- and PD/T2-weighted magnetic resonance imaging

The age of majority, which corresponds to the age of 18 years in most European countries, plays a crucial role for a large number of legal decisions. Accordingly, an increasing number of requests by authorities to forensic age estimation experts comprise the question of whether the age of 18 years has been reached by an individual. In recent years, novel study data suggested that magnetic resonance imaging (MRI) of the knee might likewise allow for the determination of majority beyond reasonable doubt. However, the data basis, especially concerning the distal femoral epiphysis (DFE), is still poor. For this reason, 392 routine MRI cases of the knee (204 males and 188 females of a Western Caucasian population, aged between 12 and 25 years) were retrospectively analyzed. T1-weighted and water-selective fat-saturated PD/T2-weighted sequences, generated at 1.5 and 3.0 T clinical MR scanners, were available. Ossification stages of the DFE were determined by means of the classification system by Vieth et al. (Eur Radiol 2018; 28:3255-3262). Both the intra-observer agreement and inter-observer agreement were found to be "very good" (κ = 0.899 and κ = 0.830). The present study confirmed that MRI of the DFE is suitable to determine majority in both sexes when stage 6 is present as the study revealed minimum ages above the age of 18 years for this stage (20.40 years in males and 20.60 years in females). Accordingly, the data represent a strong support for the so far existing database. Hence, the investigation of the knee using routine MRI appears to become a realistic alternative for forensic age estimation practice in the near future.

Post mortem computed tomography is highly sensitive for pyelonephritis. A radiologic-pathologic correlation series

Pyelonephritis is a potentially lethal disease occasionally encountered in the forensic setting. Post mortem computed tomography (PMCT) is an important investigative tool for the forensic pathologist. In particular, it may be used to document and screen disease prior to traditional autopsy methods. While the sensitivity and specificity of computed tomography for pyelonephritis is well studied in the antemortem clinical setting, the test characteristics of PMCT are not yet described in the forensic pathology literature. A series of all cases of fatal pyelonephritis identified at the Ontario Forensic Pathology Service, over the course of 1 year was studied. Radiologic, clinical and pathologic findings were reviewed. A fulsome autopsy, including histopathologic examination, was considered the gold standard for sensitivity and specificity calculations. A control group consisting of 16 cases without pyelonephritis (ex: opiate toxicity) in which both PMCT and histologic data were available by way of comparison. Sixteen cases of pyelonephritis were identified. Post mortem computed tomographical signs of pyelonephritis included asymmetric renal enlargement, perinephric fat stranding, and ectopic renal air. The most (57%) individually sensitive of these findings was perinephric fat stranding but sensitivity increased to 100% if any of the three signs were present. The control group analysis revealed the specificity of air asymmetry (81%), asymmetric renal enlargement (81%), and fat stranding (69%). PMCT findings may rule in a diagnosis of pyelonephritis, and should prompt the pathologist to grossly and microscopically examine the kidneys.

Radiographers' experiences and perspectives of forensic imaging in Australia: A qualitative study

INTRODUCTION

Forensic imaging plays a pivotal role regarding medico-legal issues by investigating the cause(s) of injuries to living or deceased individuals. There is currently a gap in the literature on forensic imaging due to limited national and international guidelines, protocols and scope of duties and responsibilities of radiographers undertaking forensic imaging. Thus, this study aimed to investigate the gap by exploring the experiences and perspectives of radiographers on forensic imaging in Australia.

METHODS

A qualitative approach collected data from fifteen purposively sampled qualified Australian radiographers through individual in-depth interviews. The verbatim transcribed data were thematically analysed.

RESULTS

Two themes were identified: 1) Radiographers' experiences of forensic imaging; 2) Radiographers' perceptions of forensic imaging within the job scope of a qualified radiographer.

CONCLUSIONS

Participants' experiences of forensic imaging ranged from anxiety to a positive experience, and others posed ethical and situational dilemmas heightened by the lack of dedicated forensic imaging protocols. While some radiographers expressed that every radiographer should conduct forensic imaging, others felt it was not mandatory.

IMPLICATIONS FOR PRACTICE

Radiographers' shared subjective experiences, thoughts and feelings provided insight into forensic imaging and the need for more significant support from educational and governing bodies.

Dental age estimation of Tibetan children and adolescents: Comparison of Demirjian, Willems methods and a newly modified Demirjian method

Tibetan ethnic group is one of the oldest ethnic groups in China and South Asia. This study set out to analyze the dental development and validate Demirjian method and Willems method in estimating dental age of Tibetan children and adolescents, and to modify Demirjian method based on Tibetan population to provide ethnic-specific reference data and a more reliable method for forensic age assessment in Tibetan ethnic group. In this study, 1951 samples aged between 4 and 15 years were retrospectively collected and analyzed. Multiple linear regression was used to establish relationship between chronological age (CA) and developmental stages of left mandibular permanent teeth. The accuracy of the modified method was tested and compared with that of Demirjian and Willems method. Results showed that dental maturity score (DMS) was significantly greater in girls than in boys in all age groups except for the 4-year age group (p < 0.05). Mean absolute error (MAE) was 0.96 years for both boys and girls by Demirjian method, and 1.06 and 1.16 years for boys and girls respectively by Willems method. Adjusted scores table was established and tested. The age of boys was overestimated by 0.13 years and the age of girls was underestimated by 0.06 years by the adjusted scores table. MAE was lower than that of the other two methods. In conclusion, Demirjian method and Willems method was not sufficiently accurate in estimating dental age of Tibetan population. The modified method was more suitable for dental age estimation of Tibetan population than Demirjian and Willems method.

[Suicidal gas embolism in hospital]

Luftembolien sind im klinischen Alltag nach traumatischen oder iatrogenen Ereignissen eine häufig zu beobachtende Entität. Fälle einer in suizidaler Absicht herbeigeführten Luftembolie sind selten. Die Konnektivität von luft- und flüssigkeitsführenden Schlauchsystemen ermöglicht die Zufuhr großer Gasmengen in kurzer Zeit mit häufig tödlichem Ausgang. Der Einsatz einer Computertomographie vor der Obduktion ist in solchen Fällen obligat und ermöglicht eine umfassende Darstellung der zugeführten Gasmengen. Wir präsentieren den ungewöhnlichen Fall einer suizidalen venösen Gaszufuhr mittels eines stationären Sauerstoffgerätes in einem Krankenhaus.

Cinematic rendering of a burst sagittal suture caused by an occipito-frontal gunshot wound

The computed tomography (CT) scan of a 19-year-old man who died from an occipito-frontal gunshot wound presented an impressive radiating fracture line where the entire sagittal suture burst due to the high intracranial pressure that arose from a near-contact shot from a 9 mm bullet fired from a Glock 17 pistol. Photorealistic depictions of the radiating fracture lines along the cranial bones were created using three-dimensional reconstruction methods, such as the novel cinematic rendering technique that simulates the propagation and interaction of light when it passes through volumetric data. Since the brain had collapsed, depiction of soft tissue was insufficient on CT images. An additional magnetic resonance imaging (MRI) examination was performed, which enabled the diagnostic assessment of cerebral injuries.

Delayed cerebral enhancement on post-mortem computed tomography due to residual contrast medium administered shortly before death

Postmortem computed tomography (CT) is currently a well-known procedure and helps in postmortem investigations. In this case report, we report a unique postmortem CT finding: delayed cerebral enhancement associated with the antemortem infusion of contrast medium. A 72-year-old female lost consciousness at a restaurant and was taken to a hospital in an ambulance. Despite resuscitation efforts, she died of hypoxic–ischemic encephalopathy caused by cardiac arrest. About 6 h before her death, she underwent enhanced antemortem CT of the head. No abnormal enhancement was observed in the cerebral parenchyma. Then, 11 h after her death, she underwent unenhanced postmortem CT, which showed bilateral hyperdense caudate nucleus and putamina, due to residual iodinated contrast medium, in addition to other characteristic findings of hypoxic–ischemic encephalopathy. The mechanism underlying this phenomenon could be the destruction of the blood–brain barrier, and/or selective vulnerability, due to hypoxic–ischemic changes in the gray matter. Enhancement of basal ganglia on postmortem CT due to antemortem infusion of iodinated contrast medium might suggest hypoxic–ischemic encephalopathy, which should be noted in postmortem CT interpretations.

Longitudinal comparison of ascites attenuation between antemortem and postmortem computed tomography

OBJECTIVE

To investigate the changes in ascites attenuation between antemortem (AMCT) and postmortem computed tomography (PMCT) analyses of the same subjects.

METHODS

Thirty-five subjects who underwent unenhanced or enhanced AMCT within 7 days before death, unenhanced PMCT, and autopsy were evaluated. In each subject, ascites attenuation was measured at similar sites on AMCT and PMCT. Attenuation changes were evaluated in 42 unenhanced AMCT/PMCT site pairs (23 subjects) and 20 enhanced AMCT/PMCT site pairs (12 subjects). Factors contributing to CT attenuation changes were also assessed, including the time interval between AMCT and PMCT, serum albumin level, estimated glomerular filtration rate, and ascites volume.

RESULTS

Significantly elevated CT attenuation was observed between enhanced AMCT and PMCT (12.2 ± 6.3 vs. 18.7 ± 10.4 Hounsfield units; paired t-test, p = 0.006), but not between unenhanced AMCT and PMCT (13.5 ± 8.9 vs. 13.4 ± 9.3; p = 0.554). A significant inverse association was observed between the degree of CT attenuation change and the time interval between enhanced AMCT and PMCT (Spearman's rank correlation coefficient, r = -0.56, p = 0.01).

CONCLUSIONS

We confirmed an elevated level of ascites attenuation on PMCT relative to AMCT in subjects who underwent enhanced AMCT shortly before death.

Postmortem magnetic resonance imaging revealed bilateral globi pallidi lesions in a death associated with prolonged carbon monoxide poisoning: a case report

A man and a woman were found dead in the same car with a burned coal briquette. The cause of death of the woman was assigned to acute carbon monoxide (CO) poisoning without difficulty based on typical findings associated with this condition, including elevation of carboxyhaemoglobin (COHb). However, the man had an unremarkable elevation of COHb and a higher rectal temperature compared to that of the woman. Postmortem computed tomography (PMCT) revealed ambiguous low-density areas in the bilateral globi pallidi. Further analysis by postmortem magnetic resonance (PMMR) imaging showed these lesions more clearly; the lesions appeared as marked high signal intensity areas on both the T2-weighted images and the fluid-attenuated inversion recovery sequences. A subsequent autopsy revealed signs of pneumonia, dehydration, starvation, and hypothermia, suggesting that the man died from prolonged CO poisoning. Both globi pallidi contained grossly ambiguous lesions, and a detailed neuropathologic investigation revealed these lesions to be coagulative necrotic areas; this finding was compatible with a diagnosis of prolonged CO poisoning. This case report shows that postmortem imaging, especially PMMR, is useful for detecting necrotic lesions associated with prolonged CO poisoning. This report further exemplifies the utility of PMMR for detecting brain lesions, which may be difficult to detect by macroscopic analysis.

Diagnostic accuracy of postmortem computed tomography for bleeding source determination in cases with hemoperitoneum

Aim

The aim of this retrospective study was to determine the accuracy of postmortem computed tomography and different radiological signs for the determination of the bleeding source in cases with hemoperitoneum confirmed at autopsy.

Methods

Postmortem computed tomography data of consecutive cases with hemoperitoneum confirmed at autopsy were reviewed by two raters, blinded to the autopsy findings. The determination of possible bleeding sources was based on the presence of the sentinel clot sign, blood or sedimented blood surrounding an organ, intraparenchymal abnormal gas distribution, and parenchymal disruption. The bleeding source and the cause of hemoperitoneum (traumatic, surgical, natural, or resuscitation) as reported in the autopsy report were noted. The survival intervals of the deceased were calculated when information about the time of an incident related to death was available in the autopsy reports.

Results

Eighty-five cases were included in the study. Postmortem computed tomography showed 79% sensitivity and 92.1% specificity for the detection of the bleeding source. The sentinel clot sign was associated with surgical or natural causes of hemoperitoneum and longer survival intervals. Sedimented blood around the bleeding source was associated with resuscitation. Abnormal gas distribution within organs and combination of multiple radiological signs provided higher sensitivity.

Conclusion

Postmortem computed tomography provides moderate sensitivity and high specificity for determining the bleeding source in cases with hemoperitoneum. Different PMCT signs are associated with different causes of hemoperitoneum and survival intervals.

Ultrasonographic evaluation of the wrist and elbow joints: A pilot study to explore a non-invasive technique for age estimation

Age estimation is a vital aspect of the process of identification. Studying the appearance and fusion of long bones is one of the most commonly used methods for age estimation. Most research conducted on age estimation using the study of the appearance and fusion of ossification centres has been roentgenographic in nature. However, X-ray examination and computed tomography examination are associated with ionisation radiation. The present study investigated the use of ultrasonography (USG) as a means of visualising ossification centres of the elbow and wrist joints for age estimation in 31 Maharashtrian boys from Ahmednagar, India. The Schmeling et al. method of grading was used to score the fusion of ossification centres, and simple and multiple linear regression models were developed for age estimation. It was found that the ossification centres of the elbow and wrist joints followed a set pattern of maturation and fusion. The ossification centres of the elbow joint fused before the ossification centres of the wrist joint. The fusion scores of proximal radial epiphyses had the highest correlation with the decimal age of the participants, making its fusion the best indicator among all the ossification centres examined in this study for age estimation. Regression models to estimate age were generated using all the ossification centres. USG was found to be suitable for the purpose of age estimation based on ease of examination, minimal ionisation risks, its non-invasive nature and clear visualisation of ossification centres.

[Bridging vein injuries in shaken baby syndrome : Forensic-radiological meta-analysis with special focus on the tadpole sign]

Shaken baby syndrome is a common variant of the abusive head trauma in infants and toddlers and is still subject of intensive research. In recent years, a number of radiological studies on the diagnostic and forensic relevance of injured bridging veins were conducted using different imaging modalities. The present article will give an overview on the current state of research in this field and will discuss the forensic implications. The meta-analysis of the seven currently existing studies revealed that injuries of the bridging veins and bridging vein thromboses, respectively, frequently appear as rounded, enlarged, and/or tubular structures. The "tadpole sign" may serve as a valuable tool for the identification of these formations. Especially, T2*/SWI (susceptibility-weighted imaging) sequences allow for good detectability of these lesions and should always be generated when abusive head trauma is suspected. In conclusion, it can be recommended that the presence of radiologically detectable bridging vein injuries should give reason to search for other manifestations of physical child abuse.

Findings from machine learning in clinical medical imaging applications - Lessons for translation to the forensic setting

Machine learning (ML) techniques are increasingly being used in clinical medical imaging to automate distinct processing tasks. In post-mortem forensic radiology, the use of these algorithms presents significant challenges due to variability in organ position, structural changes from decomposition, inconsistent body placement in the scanner, and the presence of foreign bodies. Existing ML approaches in clinical imaging can likely be transferred to the forensic setting with careful consideration to account for the increased variability and temporal factors that affect the data used to train these algorithms. Additional steps are required to deal with these issues, by incorporating the possible variability into the training data through data augmentation, or by using atlases as a pre-processing step to account for death-related factors. A key application of ML would be then to highlight anatomical and gross pathological features of interest, or present information to help optimally determine the cause of death. In this review, we highlight results and limitations of applications in clinical medical imaging that use ML to determine key implications for their application in the forensic setting.

Forensic postmortem computed tomography in suspected unnatural adult deaths

PURPOSE

Our study sought to evaluate validity of forensic postmortem CT in establishing cause of death (COD) in suspected unnatural adult death based on the reference standard of autopsy.

METHODS

In our prospective, single-center study, 64 of 94 consecutive corpses (70.7 % male, mean age: 47.4 years) who underwent CT and autopsy between November 2013 and April 2019 were included in the analysis. Primary objective was agreement between CT and autopsy on primary COD using kappa statistics. Secondary objectives were competing COD and specific pathological findings.

RESULTS

Agreement on primary COD between forensic CT and autopsy without or in consideration of toxicological and histological findings was strong (85.9 % [55 of 64 corpses]; κ = 0.83 [95 %CI: 0.74 to 0.93] and 95.3 % [61 of 64 corpses]; κ = 0.94 [95 %CI: 0.84-1.04], respectively, McNemar p = 0.03). Sensitivity and specificity of CT in identification of acute heart failure, intracranial bleeding, burns and heat shocks, gunshot wounds, polytrauma, cranio-cerebral trauma, and strangulation or hanging was 100 %, each. Acute respiratory failure was detected with a sensitivity and specificity of 100 % and 96.8 %, cuts and stab wounds with 95.2 % and 100 %, and intoxication, pneumonia, or gastrointestinal bleeding with 60.0 % and 100 %, respectively. Agreement on competing COD was moderate (51.6 %, [33 of 64 corpses]; κ = 0.47 [95 %CI: 0.40 to 0.53], p < 0.001).

CONCLUSIONS

Forensic postmortem CT, complemented by external, toxicological, and histological examination was sufficiently valid to assess primary COD in the majority of suspected unnatural deaths with few restrictions.

Noninvasive 7 tesla MRI of fatal craniocerebral gunshots - a glance into the future of radiologic wound ballistics

Compared to computed tomography (CT), magnetic resonance imaging (MRI) provides superior visualization of the soft tissue. Recently, the first 7 Tesla (7 T) MRI scanner was approved for clinical use, which will facilitate access to these ultra-high-field MRI scanners for noninvasive examinations and scientific studies on decedents. 7 T MRI has the potential to provide a higher signal-to-noise ratio (SNR), a characteristic that can be directly exploited to improve image quality and invest in attempts to increase resolution. Therefore, evaluating the diagnostic potential of 7 T MRI for forensic purposes, such as assessments of fatal gunshot wounds, was deemed essential. In this article, we present radiologic findings obtained for craniocerebral gunshot wounds in three decedents. The decedents were submitted to MRI examinations using a 7 T MRI scanner that has been approved for clinical use and a clinical 3 T MRI scanner for comparison. We focused on detecting tiny injuries beyond the wound tract caused by temporary cavitation, such as microbleeds. Additionally, 7 T T₂-weighted MRI highlighted a dark (hypo intense) zone beyond the permanent wound tract, which was attributed to increased amounts of paramagnetic blood components in damaged tissue. Microbleeds were also detected adjacent to the wound tract in the white matter on 7 T MRI. Based on the findings of radiologic assessments, the advantages and disadvantages of postmortem 7 T MRI compared to 3 T MRI are discussed with regard to investigations of craniocerebral gunshot wounds as well as the potential role of 7 T MRI in the future of forensic science.

An evaluation of statistical models for age estimation and the assessment of the 18-year threshold using conventional pelvic radiographs

The developmental patterns of the pelvic epiphyses are one of the anatomical markers used in the assessment of skeletal age and the legally relevant age threshold. In this study, four regression models and five classification models were developed for forensic age estimation and the determination of the 18-year threshold, respectively. A total of 2137 conventional pelvic radiographs (1215 males and 922 females) aged 10.00-25.99 years were analyzed, and the ossification and fusion of the iliac crest and ischial tuberosity epiphyses were scored separately. The epiphyses on both sides were used as inputs for all models. The accuracy of the regression models was compared using the mean absolute error (MAE) and root mean square error. The percentages of correct classifications were evaluated for the determination of the 18-year threshold. Support vector regression (SVR) and gradient boosting regression (GBR) showed higher accuracy for age estimation in both sexes. The lowest MAE was 1.38 years in males when using SVR and 1.16 years in females when using GBR. In the demarcation of minors and adults, the percentage of correct classification was over 92%, and the area under the receiver operating characteristic curves was over 0.91 in all models, except the Bernoulli naive Bayes classifier. This study demonstrated that the present models may be helpful for age estimation and the determination of the 18-year threshold. However, owing to the high effective dose of ionizing radiation used during conventional radiography of the pelvis, it is expected that these models will be tested with pelvic MRI for age estimation.

Pulmonary postmortem computed tomography of bacterial pneumonia and pulmonary edema in patients following non-traumatic in-hospital death

In this study, we compared the postmortem computed tomography (PMCT) findings among nonpathological lungs, lungs with bacterial pneumonia, and lungs with pulmonary edema in patients following non-traumatic in-hospital death. We studied 104 consecutive adult patients (208 lungs) who died in our tertiary care hospital and underwent PMCT and pathological autopsy (both within 2.5 days after death), and were pathologically diagnosed with nonpathological lungs, bacterial pneumonia, and pulmonary edema. Thirteen pulmonary features were assessed on the CT scans. We also examined the association between the time elapsed since death and the pulmonary findings. We observed increased lung opacities with horizontal plane formation, diffuse opacities, diffuse bronchovascular bundle thickening, symmetric opacities to the contralateral lung, and decreased segmental opacities with time elapsed since death (Cochran-Armitage test for trend). Multiple logistic regression revealed that the presence of opacities without horizontal plane formation or centrilobular opacities, and the absence of diffuse bronchovascular bundle thickening were associated with histopathological pneumonia, whereas the presence of opacities with horizontal plane formation, diffuse opacities, and interlobular septal thickening were associated with histopathological pulmonary edema. In conclusion, specific pulmonary PMCT findings increased with time elapsed since death, and some lung findings may facilitate the diagnosis of bacterial pneumonia and pulmonary edema.

The added value of postmortem magnetic resonance imaging in cases of hanging compared to postmortem computed tomography and autopsy

The purpose of this study was to evaluate the added value of postmortem magnetic resonance imaging (MRI) compared to postmortem computed tomography (CT) and autopsy in cases of fatal hanging. In addition, the study analyzed the strengths of each examination method regarding typical injuries in these cases. We investigated a cohort of 25 decedents who underwent CT, MRI and autopsy. Two radiologists assessed all MR images of the head and neck as well as the corresponding CT images. The results were compared to autopsy findings by retrospectively analyzing the autopsy reports. Postmortem MRI revealed intramuscular hemorrhages in a large number of cases, however, autopsy did not confirm all of the detected hemorrhages. CT and autopsy detected fractures in several cases, whereas MRI showed a fracture in just one single case. Other previously described vital signs and relevant findings, such as fracture-related gas bubbles, soft tissue emphysema or pneumomediastinum, were observed in only a few individual cases. MRI provided added diagnostic value in the detection of soft tissue injuries and lymph node swelling in fatal hangings. As an adjunct to autopsy, postmortem MRI may reveal additional hemorrhages, which might be missed at autopsy. Since standard MRI demonstrated low sensitivity for the detection of fractures, an additional imaging modality or autopsy is required to overcome this limitation.

Fracture patterns of the hyoid-larynx complex after fatal trauma on the neck: retrospective radiological postmortem analysis of 284 cases

PURPOSE

Fatal trauma on the neck occurs frequent in forensic cases and often results in fractures of the hyoid-larynx complex. The aim of the present study is to provide an overview of fractures in the hyoid-larynx complex that occur due to fatal trauma on the neck and can be observed by radiological evaluation.

METHODS

Radiological images from a forensic radiological database created in -BLINDED- were used for analysis. Hyoid-larynx complexes were explanted in 284 individuals who accordingly to the forensic pathologist allegedly died from fatal trauma on the neck. These explants were imaged with conventional X-rays in eight directions and a CT scan. Radiological images were analyzed for fractures, dislocations, joints, and anatomical variations by a trained analyst and a radiologist.

RESULTS

In 281/284 cases, the hyoid bone and, in 252/284 cases, the thyroid cartilage could be assessed. In 56 victims (20%), the hyoid bone was fractured, 55 times in the greater horn, 1 fracture in the body. The calcified superior horn of the thyroid showed a fracture in 101 victims (40%). The calcified cricoid cartilage was fractured in one case. Multiple fractures were found in 31/284 cases (11%). Joints between the greater horn and body of the hyoid were present in 74%.

CONCLUSION

Trauma on the neck leads most frequently to fractures of the superior horn of the thyroid cartilage and second most to fractures in the greater horn of the hyoid bone. (Forensic) radiologists should be aware of uncommon fracture locations, anatomical variations, and dislocations in the hyoid-larynx complex.

Postmortem CT and MRI findings of massive fat embolism

OBJECTIVE

To elucidate postmortem computed tomography (PMCT) and postmortem magnetic resonance (PMMR) imaging findings suggesting massive fat embolism.

MATERIALS AND METHODS

Consecutive forensic cases with PMCT and PMMR scans of subjects prior to autopsy were assessed. For PMCT, 16- or 64-row multidetector CT scans were used; for PMMR, a 1.5 T system was used. MRI sequences of the chest area included T2- and T1-weighted fast spin-echo imaging, T2*-weighted imaging, T1-weighted 3-dimensional gradient-echo imaging with or without a fat-suppression pulse, short tau inversion recovery, and in-phase/opposed-phase imaging. At autopsy, forensic pathologists checked for pulmonary fat embolism with fat staining; Falzi's grading system was used for classification.

RESULTS

Of 31 subjects, four were excluded because fat staining for histopathological examination of the lung tissue could not be performed. In three of the remaining 27 subjects, histology revealed massive fat embolism (Falzi grade III) and the cause of death was considered to be associated with fat embolism. CT detected a "fat-fluid level" in the right heart or intraluminal fat in the pulmonary arterial branches in two subjects. MRI detected these findings more clearly in both subjects. In one subject, CT and MRI were both negative. There were no positive findings in the 24 subjects that were fat embolism-negative by histology.

DISCUSSION AND CONCLUSION

In some subjects, a massive fat embolism can be suggested by postmortem imaging with a "fat-fluid level" in the right heart or intraluminal fat in the pulmonary arterial branches. PMMR potentially suggests fat embolism more clearly than PMCT.

Post-mortem computed tomography in forensic investigations of lethal gunshot incidents: is there an added value?

The aim of this study is to assess the added value of post-mortem computed tomography (PMCT) in fatal shooting incidents compared with autopsy findings. For this study, the analysis was restricted to the following four features: location of the entrance and exit wounds, internal injuries, location of projectiles or metal fragments and course of the trajectories. These features were selected because they provide essential information on the cause and manner of death. All data were retrospectively collected from medical forensic examinations of fatal shooting incidents in the Netherlands that occurred in 2010-2014. Twenty-one fatal shooting victims were included in this study, with a total of 100 trajectories. For all 100 trajectories, the forensic radiologist and pathologist came to a consensus on which examination had the highest diagnostic value for each of the four features. PMCT provides superior information on the presence of metal fragments, internal injuries and the course of trajectories. PMCT provides limited information on the discrimination of entrance and exit wounds. In conclusion, PMCT provides additional relevant information in over 60% of forensic medical examinations of deceased victims of shooting incidents. We therefore recommend adding PMCT as a standard examination in these cases.

Post-mortem computed tomography (PMCT) radiological findings and assessment in advanced decomposed bodies

PURPOSE

The aim of the study is to report radiological findings and features in advanced decomposed bodies obtained by post-mortem computed tomography (PMCT) with autopsy correlation.

MATERIALS AND METHODS

This retrospective descriptive multicentric study included 41 forensic cases examined between May 2013 and November 2016. All the bodies were PMCT-scanned prior to autopsy, and internal putrefactive state was determined using the radiological alteration index (RAI) by a radiologist with expertise in forensic radiology and a forensic pathologist trained in forensic imaging. After PMCT scans, grade of external putrefaction (GEP) was assigned during the external examination and the complete autopsy was performed by forensic pathologists.

RESULTS

The PMCT images evaluation revealed that the RAI index was > 61 in all bodies, corresponding to a moderate-massive presence of putrefactive gas. The gas grade was > II in correspondence of the major vessels, heart cavities, liver parenchyma, vertebra L3 and subcutaneous pectoral tissues, and varied from I to III in correspondence of the kidney. Cadaveric external examination revealed the presence of advanced transformative phenomena, with a GEP3 and GEP4 in most of the cases, with body swelling, eyes and tongue protrusion, body fluids expulsion and fat liquefaction.

CONCLUSION

Radiological imaging by PMCT as an adjunct to autopsy in advanced decomposed bodies represents a useful tool in detecting post-mortem gas, even in very small amounts. A correct interpretation process of the PMCT data is essential to avoid images pitfalls, due to natural decomposition that can be mistaken for pathologic processes.

Utility of contrast-enhanced computed tomography in forensic examination of a stab wound in living individuals

In cases of inflicted injury, the process of examining the patient for external injuries and documenting the findings is important for forensic assessment, including estimating or determining the type of weapon used and the circumstances of the violence. However, external examination is obviously limited in assessing internal injury. Here, we report the cases of two patients who survived stab wounds, where the findings of contrast-enhanced computed tomography (CT) performed for clinical diagnosis in the hospital were useful for forensic injury evaluation. In both cases, contrast-enhanced CT clearly displayed the injuries to the parenchymal organs and enabled the estimation of the direction and depth of the stab wounds by depicting the track and base of the wounds on acquired images. With the addition of the findings from examination of the external wound, the stab wounds in both victims were consistent with injury caused by the suspected weapon. Recently, imaging modalities including CT have become useful supplemental tools for precise forensic evaluation. Imaging findings obtained from these modalities could especially provide useful information for forensic assessment in clinical forensic medicine because examination of internal injury in the living body cannot generally be performed. Research on the precise diagnostic value of this method is required to utilize this method adequately in clinical forensic medicine.

Forensic Radiology: A Primer

RATIONALE AND OBJECTIVE

Forensic radiology is a relatively unknown subspecialty which is becoming increasingly more important. The field incorporates antemortem and postmortem imaging for the detection and documentation of various pathologies for medicolegal purposes. Postmortem imaging is increasingly used in conjunction with the traditional autopsy in a process called a "virtual" autopsy. Radiography has been a staple of forensic investigations for over a century, first used in 1896. Advanced imaging techniques such as postmortem computed tomography and postmortem magnetic resonance imaging have only recently gained acceptance in the forensic science community. Postmortem computed tomography and postmortem magnetic resonance imaging methods are now widely used in some parts of the world, while other countries including the United States have been slower to adopt these methods into their daily practice. Advanced forensic imaging is increasingly used in the courts where juries have responded positively to such presentation of forensic data. For these reasons, advanced postmortem imaging is becoming a regular part of forensic investigations. The increase in the use of forensic imaging presents a unique opportunity for radiologists to collaborate with pathologists and law enforcement officials. This paper provides an overview of forensic radiology and identifies potential challenges and opportunities.

"Perimortem" total body CT-scan examination in severely injured children: an informative insight into the causes of death

OBJECTIVE

To report routine practice of "perimortem" CT-scan imaging to determine the causes of death in children dying from severe accidental injuries within the first hours following hospital admission.

SETTINGS

Trauma center of a University Pediatric Hospital.

METHODS

A retrospective study was conducted in children (0 to 15 years old) referred for severe trauma (GCS ≤ 8) to a regional pediatric trauma center, presenting with at least spontaneous cardiac rhythm and dying within the first 12 h after admission. "Perimortem" CT-scan consisted in high-resolution, contrast-enhanced, full-body CT-scan imaging, performed whatever child's clinical status. Lethal and associated lesions found were analyzed and classified according to validated scales. The comparison between clinical and radiological examinations and CT-scan findings evaluated the accuracy of clinical examination to predict lethal lesions.

RESULTS

CT-scan performed in 73 children detected 132 potentially lethal lesions, at least 2 lesions in 63%, and 1 in 37% of the cases. More frequent lethal lesions were brain (43%), and chest injuries (33%), followed by abdominal (12%), and cervical spine injuries (12%). Clinical and minimal radiological examinations were poorly predictive for identifying abdominal/chest lesions. Clinical and imaging data provided to the medical examiner were considered sufficient to identify the cause of death, and to deliver early burial certificates in 70 children. Only three legal autopsies were commanded.

CONCLUSIONS

Perimortem CT imaging could provide an insight into the causes of death in traumatized children. Performed on an emergency basis near death, it eliminates the difficulties encountered in forensic radiology. It could be a possible alternative to full-scale forensic examination, at least regarding elucidation of the potential, or highly probable causes of death.

State of the art in post-mortem computed tomography: a review of current literature

Computed tomography (CT) and other advanced diagnostic imaging techniques are gaining popularity in forensic pathology. This paper aims to define and offer complete and easily accessible "state of the art" for post-mortem computed tomography (PMCT), by reviewing the latest international literature. The proposed format answers the "five Ws" that follows: (1) What: We report the different kinds of CT scan and settings generally used in post-mortem imaging. The machine most employed is a 8/16-slice spiral CT, usually without contrast enhancement. The introduction of some variables, such as CT-guided biopsies, post-mortem ventilation, and PMCT angiography is becoming increasingly useful. (2) Why: Literature highlights the many advantages of PMCT. Limitations can be partly overcome by modern imaging techniques and combined evaluation with traditional autopsy. (3) Who: Most authors agree that collaboration between different specialists, i.e., radiologists and pathologists, is the best scenario, since radiologic, anatomic, and forensic skills are needed simultaneously. The most important human factor is "teamwork". (4) When: Literature provides no absolute limits for performing PMCT. Some authors have tested PMCT as a replacement for conventional autopsy but found some limitations. Others evaluated PMCT as a guide or screening tool for traditional autopsy. (5) Where: Many research groups around the world have performed studies on the use of PMCT. Although few countries adopt PMCT in routine practice, its use is rapidly spreading.

Is CT bulletproof? On the use of CT for characterization of bullets in forensic radiology

Purpose

Forensic investigations could benefit from non-invasive in situ characterization of bullets. Therefore, the use of CT imaging was explored for the analysis of bullet geometry and composition. Bullet visualization with CT is challenging as the metal constituents suffer from excessive X-ray attenuation due to their high atomic number, density, and geometry.

Methods

A metal reference phantom was developed containing small discs of various common metals (aluminum, iron, stainless steel, copper, brass, tungsten, and lead). CT images were acquired with 70–150 kVp and 200–400 mAs and were reconstructed using an extended Hounsfield unit (HU) scale (− 10,240 to + 30,710). For each material, the mean CT number (HU) was measured to construct a metal database. Different bullets (n = 11) were scanned in a soft tissue-mimicking phantom. Bullet size and shape were measured, and composition was evaluated by comparison with the metal database. Also, the effect of bullet orientation within the CT scanner was evaluated.

Results

In the reference phantom, metals were classified into three groups according to their atomic number (Z): low (Z ≤ 13; HU < 3000), medium (Z = 25–30; HU = 13,000–20,000), and high (Z ≥ 74; HU > 30,000). External bullet contours could be accurately delineated. Internal interfaces between jacket and core could not be identified. Cross-sectional spatial profile plots of the CT number along bullets’ short axis revealed beam hardening and photon starvation effects that depended on bullet size, shape, and orientation within the CT scanner. Therefore, the CT numbers of bullets were unreliable and could not be used for material characterization by comparison with the reference phantom.

Conclusion

CT-based characterization of bullets was feasible in terms of size and shape but not composition.

Assessment of a simple method of heart weight estimation by postmortem computed tomography

BACKGROUND

Measurement of heart weight is important when investigating cause of death, but there is presently no satisfactory method of heart weight estimation by postmortem computed tomography (PMCT).

METHOD

We investigated 33 consecutive cases that underwent both PMCT and autopsy between February 2008 and June 2014. Heart and left ventricular (LV) weights were calculated by PMCT morphometry. We used a simple method to estimate LV weight: We assumed that LV was an ellipsoid and multiplied its volume on PMCT with myocardial specific gravity. We then compared the various heart and LV weights using linear regression. The calculated and estimated LV weights on PMCT were also compared.

RESULTS

It was not possible to predict heart weight at autopsy from PMCT (R² = 0.53). However, heart weight at autopsy could be accurately predicted from LV weight calculated by PMCT (R² = 0.77). In addition, there was a strong correlation between the estimated and calculated LV weights by PMCT (R² = 0.92). Heart weight at autopsy could also be accurately predicted using the PMCT-estimated LV weight (R² = 0.72).

CONCLUSION

Heart weight at autopsy could be accurately predicted using a simple method in which LV volume was assumed to be an ellipsoid on PMCT.

Self-inflicted long bone fractures for insurance fraud

Self-inflicted fractures simulating traffic accident represent a new social fraud opportunity for criminality. Recognising scams through an increase of awareness of existence of self-inflicted arm fractures for insurance fraud could help community health workers to report these injuries to the competent authorities. In this article, authors have recognised an unusual but consistent pattern of upper and lower limb fractures whose incidence does not coincide in numerical terms with what is reported in literature. The aim of the present study is to describe fracture patterns observed over the past 2 years. Further, authors describe clinical presentations of these fractures and attempt to define a possible mechanism of these types of injuries.

Delayed rupture of a vertebral artery laceration: a case report and challenges for the forensic pathologist

Vertebral artery laceration/dissection (VALD) resulting in fatal subarachnoid hemorrhage (SAH) is a rare, but well-known phenomenon encountered in the forensic setting. Delayed ruptures are exceptionally rare, and pose several challenges to the forensic pathologist. In this paper we present a case of a 47-year-old male who collapsed suddenly following recent complaints of a headache and a reported seizure. He had a reported history of potential head trauma that occurred several days prior. Attempts at resuscitation were unsuccessful, and an autopsy examination was ordered. Computer tomography (CT), autopsy, histological and ancillary studies were performed. External examination showed mild, healing trauma to the head and upper limbs, and pre-autopsy CT demonstrated a SAH. Examination of the brain showed basally oriented SAH, and there was a laceration of the left vertebral artery. Histological examination demonstrated a delayed rupture, and there was no significant blood vessel abnormality. Molecular testing was negative for collagen vascular disorders. Delayed rupture of the vertebral arteries following head trauma is rare. The presence of remote and/or mild trauma may be difficult to establish at autopsy, and it is important to identify underlying aortopathies. Several autopsy techniques and ancillary studies should be performed in these cases.

Postmortem radiological case series of acetabular fractures after fatal aviation accidents

The purpose of this study was to describe radiological fracture patterns of the acetabulum sustained after fatal small aircraft aviation accidents, aiming at facilitating a better understanding of trauma mechanisms in a forensic setting. Postmortem conventional radiographs or CT scans of 29 victims of 20 small aircraft aviation accidents were analyzed for skeletal acetabular trauma. Among the 29 fatalities (27 males and 2 females, median age 55 years (range: 21–76 years)), 20 victims had pelvic fractures (69%), of which 19 victims (66%) had one or more acetabular fractures. Bilateral acetabular fractures occurred in 11 victims. When considering left and right acetabula in each victim as separate entities, 38 of the 58 acetabula included in this case series exhibited one or more fractures. Both the anterior and posterior acetabular columns were fractured in 28 acetabula. Acetabular fractures were frequently encountered in this series of 29 victims of small fatal aircraft accidents. Fractures of the acetabulum occur from ventrally directed impact (i.e. to the knee) or laterally directed impact (i.e. to the greater trochanter of the femur). Radiological descriptions of the fracture patterns can therefore aid in the forensic analysis of the mechanism of trauma in aviation accidents. Postmortem multi-slice CT scan images are preferrable in the assessment of acetabular fractures.

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.

Forensic Radiology: An Update

Forensic radiology is a specialized area of medical imaging using radiological techniques to assist physicians and pathologists in matters related to the law. The forensic application of diagnostic medical radiology can be applied in many fields; the prime target of evaluation is the osseous skeleton, but soft tissues and abdominal and thoracic viscera may offer key findings. The technological progress in clinical radiology provides a lot of potential tools to forensic radiology, allowing wider fields of applications in this matter.

Virtual computed tomography morphometry of the patella for estimation of sex using postmortem Japanese adult data in forensic identification

In forensic anthropological identification of human remains and single bones, computed tomography (CT) data analysis facilitates volumetric and radiographic density analyses, and a recently developed automated analysis system markedly improved the performance, accuracy, and reproducibility of three-dimensional (3-D) reconstruction. The present study aimed to investigate virtual CT morphometry of the patella for the estimation of sex using postmortem CT data of forensic autopsy cases of Japanese individuals aged ≥18 years (total n=220; 110 males and 110 females; estimated postmortem interval <88h), especially with regard to the efficacy of 3-D bone volumetry. Sex-related differences were detected for all parameters (males>females; p<0.0001), but the differences were the most notable for bone mass volume; the estimated cut-off values (cm³) for discriminating males and females were 20.35 with a sensitivity and specificity of 0.85 and 0.91 for the left side and 19.96 with a sensitivity and specificity of 0.83 and 0.92 for the right side, respectively. The mean CT value showed an age-dependent decrease and was particularly low in females aged >60years. These findings indicate the efficacy of virtual CT morphometry of the patella using an automated analyzer for sex estimation.

Comparative radiologic identification with standardized single CT images of the paranasal sinuses-Evaluation of inter-rater reliability

The aim of this study was to assess the reproducibility of a standardized image for personal identification (SIPI), used in the comparative analysis of paranasal sinuses, and test the effect of inaccurate reformation of the SIPI on suitability for comparative identification. Five raters with different professional backgrounds independently reformatted SIPIs from ten post-mortem head CTs. Inter-rater, intra-rater agreement as well angular deviations between reformatted SIPI images and reference SIPI images were calculated. Second, raters assessed the suitability of 70 accurately and inaccurately reformatted SIPIs for identification with a 4-point Likert scale. Inter-rater agreement as well as levels of significance regarding image suitability were calculated. Inter-rater agreement regarding reproducibility of SIPI reformation was excellent (inter-rater correlation coefficient (ICC) 0.9995, intra-rater ICC 0.9983). Deviation between the angular dimensions of the reformatted SIPIs and the reference SIPIs was ≤1° in 94% of all 300 measurements. Inter-rater agreement regarding the effect of inaccurate SIPI reformation on suitability for comparative identification was fair (ICC 0.6809). There was no statistically significant difference between raters' evaluation of image suitability (p=0.9755). This study shows that the standardized image for personal identification can be accurately reformatted by different raters with varying professional backgrounds. In addition, raters agree that inaccurately reformatted SIPIs are still suitable for comparative identification in the majority of cases.

Accuracy of non-contrast PMCT for determining cause of death

The aim of this study was (1) to compare levels of accuracy regarding the categorization of causes of death between non-contrast post-mortem computed tomography (PMCT) and the final forensic report as well as between autopsy and the final forensic report, and (2) to assess levels of confidence regarding the categorization of causes of death after non-contrast PMCT and after autopsy. This prospective study was conducted over a 5 month period during which 221 cases were admitted to our institute for forensic investigations. Whole-body PMCT and forensic autopsy were performed in every case. Of these, 101 cases were included in the final study population. Inclusion criteria were: (1) age > 18 years, (2) presence of at least one of the two principal investigators at the time of admission. One radiologist and one forensic pathologist independently read all PMCT datasets using a report template. Cause of death category and confidence levels were determined by consensus. Forensic autopsy was performed by two forensic pathologists; both unblinded to imaging results. Both post-imaging and post-autopsy cause of death categorization were compared against the final cause of death, as stated in the forensic expert report, which included findings from histology and/or toxicology. Accuracy of post-imaging cause of death categorization in reference to the final cause of death category was substantial (82%, 83/101 cases, Kappa 0.752). Accuracy of post-autopsy cause of death categorization in reference to the final cause of death category was near perfect (89%, 90/101 cases, Kappa 0.852). Post-imaging sensitivity and specificity regarding the categorization of causes of death were 82% and 97%, respectively. Post-autopsy sensitivity and specificity regarding the categorization of causes of death were 89% and 98%, respectively. There was a high consistency between the accuracy of post-imaging cause of death categorization and post-imaging levels of confidence. There was less consistency between accuracy of post-autopsy cause of death categorization and post-autopsy levels of confidence. In this study categorization of causes of death based on non-contrast enhanced PMCT alone, and on PMCT and macroscopic autopsy together, proved to be consistent with the final cause of death-category as determined based on all available information including PMCT, autopsy, and (if available) histology and/or toxicology in more than 82% and 89% of all cases, respectively. There was higher consistency between levels of confidence and accuracy of causes of death categorization was higher post-imaging than post-autopsy. These results underline the fact that the diagnostic potential of PMCT goes beyond the assessment of trauma cases.

Antemortem identification by fusion of MR and CT of the paranasal sinuses

Radiologic forensic identification is usually performed by comparing antemortem and postmortem radiographs. While computed tomography (CT) has become a valuable addition to radiologic identification, magnetic resonance (MR) imaging has only rarely been used for this purpose. In our case, identification was accomplished using fused MR- and CT images in a survivor of a gunshot injury to the head. This case supports and highlights the possibility to perform intermodality radiologic identification comparing preexisting MR imaging to subsequently aquired CT data in living (or deceased) humans as long as manual modifications of windowing, color and contrast enable differentiation of the two modalities in the fused image.

Differentiation of hemopericardium due to ruptured myocardial infarction or aortic dissection on unenhanced postmortem computed tomography

The aim of the study was to evaluate unenhanced postmortem computed tomography (PMCT) in cases of non-traumatic hemopericardium by establishing the sensitivity, specificity and accuracy of diagnostic criteria for the differentiation between aortic dissection and myocardial wall rupture due to infarction. Twenty six cases were identified as suitable for evaluation, of which ruptured aortic dissection could be identified as the underlying cause of hemopericardium in 50% of the cases, and myocardial wall rupture also in 50% of the cases. All cases underwent a PMCT and 24 of the cases also underwent one or more additional examinations: a subsequent autopsy, or a postmortem magnetic resonance (PMMR), or a PMCT angiography (PMCTA), or combinations of the above. Two radiologists evaluated the PMCT images and classified each case as "aortic dissection", "myocardial wall rupture" or "undetermined". Quantification of the pericardial blood was carried out using segmentation techniques. 17 of 26 cases were correctly identified, either as aortic dissections or myocardial ruptures, by both readers. 7 of 13 myocardial wall ruptures were identified by both readers, whereas both readers identified correctly 10 of 13 aortic dissection cases. Taking into account the responses of both readers, specificity was 100% for both causes of hemopericardium and sensitivity as well as accuracy was higher for aortic dissections than myocardial wall ruptures (72.7% and 87.5% vs 53.8% and 75% respectively). Pericardial blood volumes were constantly higher in the aortic dissection group, but a statistical significance of these differences could not be proven, since the small count of cases did not allow for statistical tests. This study showed that diagnostic criteria for the differentiation between ruptured aortic dissection and myocardial wall rupture due to infarction are highly specific and accurate.

Comparison of the cardiothoracic ratio between postmortem and antemortem computed tomography

As postmortem imaging has gained prominence as a supplement to traditional autopsy, it is important to understand the normal postmortem changes to enable the accurate evaluation of postmortem imaging. No studies have evaluated the postmortem changes in cardiothoracic ratio (CTR) compared with antemortem images in the same subjects. We studied 147 consecutive subjects who underwent antemortem and postmortem CT, and autopsy. Postmortem CT was performed <23h after death and was followed by autopsy. The subjects were divided into three groups: normal heart, old myocardial infarction, and CPR-treated hearts. CTR was compared between antemortem and postmortem CT using paired t tests, which revealed that the CTR was greater on postmortem CT than on antemortem CT in all groups (mean CTR: 0.53±0.06vs. 0.50±0.06, respectively; P<0.01). Sex, age, time elapsed since death, and the causes of death were examined as potential confounding factors for the postmortem changes in CTR, but no significant associations were found. Receiver-operating characteristic (ROC) curves were used to determine CTR values for cardiomegaly, which was defined according to the autopsy weight of the heart. The area under the ROC curve was 0.71 (95% confidence interval 0.63-0.79). The CTR threshold of 0.54 identified cardiomegaly with the greatest accuracy, compared with the general threshold of 0.50. In conclusion, the CT-determined CTR increases after death, irrespective of the heart's condition. We should be cautious of overdiagnosis of cardiomegaly on postmortem CT, and new criteria for interpreting cardiomegaly on postmortem CTR are needed.

Severe pelvic injury: vascular lesions detected by ante- and post-mortem contrast medium-enhanced CT and associations with pelvic fractures

OBJECTIVES

The objectives of this study were to compare arterial and venous contrast medium extravasation in severe pelvic injury detected by ante- and post-mortem multi-detector CT (MDCT) and determine whether vascular injury is associated with certain types of pelvic fracture.

METHODS

We retrospectively included two different cohorts of blunt pelvic trauma with contrast medium extravasation shown by MDCT. The first group comprised 49 polytrauma patients; the second included 45 dead bodies undergoing multi-phase post-mortem CT-angiography (MPMCTA). Two radiologists jointly reviewed each examination concerning type, site of bleeding and pattern of underlying pelvic ring fracture.

RESULTS

All 49 polytrauma patients demonstrated arterial bleeding, immediately undergoing subsequent angiography; 42 (85%) had pelvic fractures, but no venous bleeding was disclosed. MPMCTA of 45 bodies revealed arterial (n = 33, 73%) and venous (n = 35, 78%) bleeding and pelvic fractures (n = 41, 91%). Pelvic fracture locations were significantly correlated with ten arterial and six venous bleeding sites in dead bodies, with five arterial bleeding sites in polytrauma patients. In dead bodies, arterial haemorrhage was significantly correlated with the severity of pelvic fracture according to Tile classification (p = 0.01), unlike venous bleeding (p = 0.34).

CONCLUSIONS

In severe pelvic injury, certain acute bleeding sites were significantly correlated with underlying pelvic fracture locations. MPMCTA revealed more venous lesions than MDCT in polytrauma patients. Future investigations should evaluate the proportional contribution of venous bleeding to overall pelvic haemorrhage as well as its clinical significance.

Can postmortem computed tomography detect antemortem hypoxic-ischemic encephalopathy?

The purpose of this study was to evaluate the usefulness of brain postmortem computed tomography (PMCT) findings for the detection of global hypoxia or hypoperfusion leading to hypoxic-ischemic encephalopathy (HIE) prior to death. Cadavers of individuals who died from non-traumatic causes were subjected to PMCT and pathological autopsy. Cases with an episode of cardiopulmonary arrest, hypoxia, or hypoperfusion that required intensive respiratory management at least 24 h before death and exhibited findings of HIE in conventional autopsy (HIE group, n = 6) were compared with those without such episodes prior to death (control group; overall, n = 37; age-matched, n = 8) with regard to four parameters: (1) width of the central sulcus (CS), (2) attenuation difference at the basal ganglia (BG) level, (3) attenuation difference between cerebral gray matter (GM) and cerebral white matter (WM), and (4) attenuation difference between cerebellar GM and cerebral GM. The results revealed significant differences in the width of the CS (P < 0.001), attenuation difference at the BG level (P < 0.001), and attenuation difference between cerebral GM and cerebral WM (P = 0.009) between the HIE group and the overall control group. When the age-matched control group and the HIE group were compared, there was a significant difference in the width of the CS (P = 0.026) and attenuation difference at the BG level (P < 0.001). Our results suggest that effacement of the sulcus of the cerebral hemisphere and the loss of contrast at the BG level on brain PMCT indicate the existence of HIE prior to death.

Performance of post-mortem CT compared to autopsy in children

INTRODUCTION

Radiological techniques such as non-enhanced post-mortem computed tomography (PMCT) play an increasingly important role in death investigations, especially in cases of non-medicolegal context of death, where the consent of the next of kin is required to perform autopsy. Such consent is often difficult to obtain for deceased children, and radiological methods may be an acceptable alternative. The aim of our study was to evaluate the performance of PMCT explorations compared to medicolegal conventional autopsies in children and its potential usefulness in non-medicolegal situations.

METHODS

We retrospectively reviewed a group of 26 children aged 0-12 years who died of different causes, which were investigated by both conventional autopsy and PMCT. We compared the findings extracted from radiological and autopsy reports. All findings were grouped according to their importance with respect to cause of death and to the anatomical structure they covered: organs, vascular system, soft tissue, and skeletal system.

RESULTS

A significantly larger number of findings were detected by autopsy compared to PMCT. Autopsy proved to be superior to PMCT, notably at detecting organ, soft tissue, and vascular findings, while PMCT was superior at detecting bone findings. However, no statistically significant differences were found between the methods concerning the essential findings used to define the cause of death.

CONCLUSIONS

In children, PMCT was less sensitive than conventional autopsy for detecting general findings. However, most essential findings were detected by both methods. PMCT was superior to autopsy for the detection of bone lesions in children.

ADVANCES IN KNOWLEDGE

Up to today, very rare literature exists concerning PMCT in children, especially in a forensic setting. This article investigates the advantages and limitations of PMCT compared to autopsy in a unique study group and discusses possibilities for future developments.

Cardiac dilatation index as an indicator of terminal central congestion evaluated using postmortem CT and forensic autopsy data

Previous studies demonstrated possible application of postmortem quantitative CT data analysis of the heart and lung in situ to investigate terminal cardiopulmonary pathophysiology. The present study analyzed virtual CT morphometric and autopsy data of the heart to investigate terminal central congestion in forensic autopsy cases (n=113, within 3 days postmortem); the virtual total heart weight in situ was estimated using CT morphometry, and the difference from and ratio to the measured weight at autopsy were calculated as indicators of heart blood pooling and the cardiac dilatation index (CDI) before dissection, respectively. There were substantial differences between the estimated heart blood pooling in situ and volume recovered at autopsy, including a characteristic decrease in drowning, alcohol/sedative-hypnotic intoxication and sudden cardiac death (SCD), possibly due to blood redistribution after thoracic dissection. The estimated in situ heart blood pool and CDI values were higher in SCD but lower in fatal hemorrhage and hemopericardium, as well as in acute mechanical asphyxiation and hyperthermia (heatstroke). In addition, there was a significant difference in heart blood pooling between mechanical asphyxiation or drowning and SCD. The CDI was significantly lower in fatal hyperthermia (heatstroke) than in drowning, fatal methamphetamine abuse, alcohol/sedative-hypnotic intoxication and SCD. These findings suggest the usefulness of applying the CDI and postmortem heart blood volume in situ as supplementary indicators of terminal central congestion, especially for investigating deaths from hemorrhage, hemopericardium, hyperthermia (heatstroke) and SCD.