Post-mortem CT imaging of the lungs: pathological versus non-pathological findings

The role of video-assisted thoracoscopy in chest trauma: a retrospective monocentric experience

Video-assisted thoracoscopy (VAT) plays an essential role in the exploration of pleural cavity after thoracic trauma, although some doubts about the precise and specific indications persist. This study examines the eligibility criteria for videothoracoscopy and establishes the ideal timing for VAT. Between January 2011 and November 2022, we observed 923 polytraumatized patients. All patients underwent computed tomography (CT) scan total body with and without contrast enhancement. Two hundred and nine patients carried out VAT within 10 ± 2 h of injury while 8 patients after 20 ± 1 h. The Injury Severity Score (ISS) was 31 ± 1 and the Glasgow Coma Scale was 14.1 ± 0.3 upon arrival at the hospital. One hundred and nineteen patients displayed hemothorax (55%), 62 hemopneumothorax (28.5%), 21 penetrating wound (9.6%), 10 pneumothorax (4.6%) and 5 chylothorax (2.3%). In 18 patients (8.3%) without vascular, diaphragmatic, or parenchymal lesion the treatment consisted in chest tube placement. VAT was converted to video-assisted thoracoscopic surgery (VATS) in 190 patients (87.5%), to open surgery in 8 (3.7%) and to laparoscopy in 1 (0.5%). Twelve patients (5.5%) with diaphragm ruptures < 5 cm in diameter were treated by separate stitches suture in VATS. Only eight postoperative complications (4 pneumonia, three atelectasis and one pulmonary embolism) out of 217 VAT, positively resolved with medical treatment, were noted exclusively in patients undergoing minimally invasive approach 20 ± 1 h after trauma. Early VAT in selected patients is a safe and easy procedure that ensure a quick diagnosis of lesions and an accurate management of the most thoracic injuries among trauma patients. The prompt identification of injuries, to avoid life-threatening conditions requiring rapid intervention, responds to medico-legal needs to which VAT fulfills.

Postmortem chest computed tomography in COVID-19: A minimally invasive autopsy method

Objectives

Performing autopsies in a pandemic scenario is challenging, as the need to understand pathophysiology must be balanced with the contamination risk. A minimally invasive autopsy might be a solution. We present a model that combines radiology and pathology to evaluate postmortem CT lung findings and their correlation with histopathology.

Methods

Twenty-nine patients with fatal COVID-19 underwent postmortem chest CT, and multiple lung tissue samples were collected. The chest CT scans were analyzed and quantified according to lung involvement in five categories: normal, ground-glass opacities, crazy-paving, small consolidations, and large or lobar consolidations. The lung tissue samples were examined and quantified in three categories: normal lung, exudative diffuse alveolar damage (DAD), and fibroproliferative DAD. A linear index was used to estimate the global severity of involvement by CT and histopathological analysis.

Results

There was a positive correlation between patient mean CT and histopathological severity score indexes - Pearson correlation coefficient (R) = 0.66 (p = 0.0078). When analyzing the mean lung involvement percentage of each finding, positive correlations were found between the normal lung percentage between postmortem CT and histopathology (R=0.65, p = 0.0082), as well as between ground-glass opacities in postmortem CT and normal lungs in histopathology (R=0.65, p = 0.0086), but negative correlations were observed between ground-glass opacities extension and exudative diffuse alveolar damage in histological slides (R=-0.68, p = 0.005). Additionally, it was found is a trend toward a decrease in the percentage of normal lung tissue on the histological slides as the percentage of consolidations in postmortem CT scans increased (R =-0.51, p = 0.055). The analysis of the other correlations between the percentage of each finding did not show any significant correlation or correlation trends (p ≥ 0.10).

Conclusions

A minimally invasive autopsy is valid. As the severity of involvement is increased in CT, more advanced disease is seen on histopathology. However, we cannot state that one specific radiological category represents a specific pathological correspondent. Ground-glass opacities, in the postmortem stage, must be interpreted with caution, as expiratory lungs may overestimate disease.

Efficacy of postmortem CT and tissue sampling in establishing the cause of death in clinical practice: a prospective observational study

AIMS

The aim of this study is to evaluate whether agreement with autopsy-determined cause of death (COD) increases by use of postmortem CT (PMCT) or PMCT in combination with postmortem sampling (PMS), when compared with clinical assessment only.

METHODS

This prospective observational study included deceased patients from the intensive care unit and internal medicine wards between October 2013 and August 2017. The primary outcome was percentage agreement on COD between the reference standard (autopsy) and the alternative postmortem examinations (clinical assessment vs PMCT or PMCT+PMS). In addition, the COD of patient groups with and without conventional autopsy were compared with respect to involved organ systems and pathologies.

RESULTS

Of 730 eligible cases, 144 could be included for analysis: 63 underwent PCMT without autopsy and 81 underwent both PMCT and autopsy. Agreement with autopsy-determined COD was significantly higher for both PMCT with PMS (42/57, 74%), and PMCT alone (53/81, 65%) than for clinical assessment (40/81, 51%; p=0.007 and p=0.03, respectively). The difference in agreement between PMCT with PMS and PMCT alone was not significant (p=0.13). The group with autopsy had a significantly higher prevalence of circulatory system involvement and perfusion disorders, and a lower prevalence of pulmonary system involvement.

CONCLUSION

PMCT and PMS confer additional diagnostic value in establishing the COD. Shortcomings in detecting vascular occlusions and perfusion disorders and susceptibility to pulmonary postmortem changes could in future be improved by additional techniques. Both PMCT and PMS are feasible in clinical practice and an alternative when autopsy cannot be performed.

Comparison between pre-mortem and post-mortem cadaveric images for use with augmented reality headsets during dissection

PURPOSE

Medical training has undergone many transformations to incorporate diagnostic imaging along side anatomical education. Post-mortem computed tomography (CT) scanning of body donors prior to dissection has been proposed. However, it poses challenges secondary to the embalming process and other post-mortem physiological changes that significantly alter the imaging quality. The purposes of this study were to compare the accuracy of pathology identification on pre- and post-mortem CT scans of body donors and to assess the integration of those scans in a dissection-based course, where these images were overlaid onto body donors using augmented reality (AR).

METHODS

Participants in this study included 35 fourth year medical students, 5 radiology residents and 3 radiologists. A convergent, parallel mixed methods design was employed with quantitative measures that included statistical analyses of a double-blinded comparison of pathological lesions recognition, on both image sets, the group responses to a study participant survey and the login access data from imaging repository. The study also included qualitative analysis of post-elective structured interviews.

RESULTS

The double-blinded comparison revealed that staff radiologists can only identify, on post-mortem images, 54.8% of the pathologies that they were able to detect on the pre-mortem scans. Analyses of the surveys and login access data reveal that 60% of radiology residents and 56% of students preferred pre-mortem scans and used those scans more often than post-mortem scans (67 access vs 36, respectively). However, post-mortem scans were significantly preferred when used to overlay onto body donors using AR (p = 0.0047).

CONCLUSION

These results show that post-mortem imaging can be valuable alongside pre-mortem imaging, as they represent the most concordance between the anatomical structures and pathologies seen on the images and what is being dissected.

Post-mortem changes of the vascular system-a thanatological study using multidetector computed tomography

Forensic pathologists have to deal with post-mortem changes of the human body. Those post-mortem phenomena are familiar and largely described in thanatology. However, knowledge about the influence of post-mortem phenomena on the vascular system is more limited, except for the apparition and development of cadaveric lividity. The introduction of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the forensic field and the expansion of their usage in medico-legal routine, allow for exploring the inside of corpses differently and may play a part in the understanding of thanatological processes. This study aimed to describe post-mortem changes in the vascular system by investigating the presence of gas and collapsed vessels.We investigated post-mortem MDCT data of 118 human bodies. Cases with internal/external bleeding or corporal lesion allowing contamination with external air were excluded. Major vessels and heart cavities were systematically explored and a trained radiologist semi-quantitatively assessed the presence of gas.Collapsed veins were observed in 61.9% of cases (CI95% 52.5 to 70.6) and arteries in 33.1% (CI95% 24.7 to 42.3). Vessels most often affected were for arteries: common iliac (16.1%), abdominal aorta (15.3%), external iliac (13.6%), and for veins: infra-renal vena cava (45.8%), common iliac (22.0%), renal (16.9%), external iliac (16.1%), and supra-renal vena cava (13.6%). Cerebral arteries and veins, coronary arteries, and subclavian vein were unaffected. The presence of collapsed vessels was associated with a minor degree of cadaveric alteration. We observed that arteries and veins follow the same pattern of gas apparition for both the quantity and the location.In post-mortem radiology, collapsed vessels and intravascular gas are frequently visualized and as a result of all post-mortem changes, the assessment of the distribution of blood can be confusing. Therefore, knowledge of thanatological phenomena is crucial to prevent post-mortem radiological misapprehensions and possible false diagnoses.

Virtual autopsy in SARS-CoV-2 breakthrough infection: a case report

It is well documented that COVID-19 vaccines are effective tools for limiting the pandemic. Unfortunately, as is true for all vaccines, SARS-CoV-2 infection in vaccinated individuals is still possible.

We present an autopsy case of SARS-CoV-2 infection after vaccination (“breakthrough infection”) in an elderly man with several comorbidities where post-mortem CT scan was performed. The death was histologically attributed to cardio-respiratory arrest due to ischemic heart failure related to superinfected COVID-19 pneumonia and pre-existing comorbidities. For the first time in the literature, PMCT imaging related to a fatal, autopsy case of breakthrough SARS-CoV-2 infection is reported. PMCT of the lungs, in accordance with histopathological results, showed few signs of COVID-19 pneumonia, large area of consolidation in the right lower lobe, interpreted as bronco-pneumonic focus, and hypostasis.

These findings were well-correlated with the previously reported literature about both PMCT and clinical CT imaging of the lungs in non-vaccinated individuals with early COVID-19 pneumonia and about pulmonary clinical CT imaging in COVID-19 pneumonia in breakthrough SARS-COV-2 infections.

Further studies are needed to cover the whole spectrum of PMCT lung imaging in fatal breakthrough SARS-CoV-2 infection, however, this case represent a first step for exploring this difficult challenge during SARS-CoV-2 pandemic using virtual autopsy.

Post-Mortem Computed Tomography Pulmonary Findings in Harbor Porpoises (Phocoena phocoena)

Simple Summary

The use of cross-sectional imaging techniques to examine the cause of death and health status of deceased animals is increasing in both veterinary and wildlife conservation programs, including species of whales and dolphins. Lung disease is common in harbor porpoises (Phocoena phocoena), a small whale species that regularly washes up on the coast in North Sea-bordering countries. This study aimed to describe lung changes visible in computed tomographic (CT) images of recently deceased harbor porpoises before pathological dissection was performed, including comparison of these two examination methods. Despite frequently visible signs of body decomposition, several lung abnormalities (collapsed lung, fluid in the airways, lung mineralization) were more often seen on the CT images. In general, lung changes could be described in more detail compared to gross dissection. CT images of lungs of recently deceased harbor porpoises can therefore be used to guide gross dissection, leading to more specific findings and potentially a more complete understanding of the circumstances leading to the death of the porpoise, assessment of the population, and ultimately, ecosystem health.

Abstract

The application of whole-body post-mortem computed tomography (PMCT) in veterinary and wildlife post-mortem research programs is advancing. A high incidence of pulmonary pathology is reported in the harbor porpoise (Phocoena phocoena). In this study, the value of PMCT focused on pulmonary assessment is evaluated. The objectives of this study were to describe pulmonary changes as well as autolytic features detected by PMCT examination and to compare those findings with conventional necropsy. Retrospective evaluation of whole-body PMCT images of 46 relatively fresh harbor porpoises and corresponding conventional necropsy reports was carried out, with a special focus on the respiratory tract. Common pulmonary PMCT findings included: moderate (24/46) to severe (19/46) increased pulmonary soft tissue attenuation, severe parasite burden (17/46), bronchial wall thickening (30/46), and mild autolysis (26/46). Compared to conventional necropsy, PMCT more frequently identified pneumothorax (5/46 vs. none), tracheal content (26/46 vs. 7/46), and macroscopic pulmonary mineralization (23/46 vs. 11/46), and provided more information of the distribution of pulmonary changes. These results indicate that PMCT adds information on pulmonary assessment and is a promising complementary technique for necropsy, despite the frequent presence of mild autolytic features.

Analysis of the role of PMCT during the COVID-19 pandemic: a systematic review

Objectives

During COVID-19 pandemic PMCT has been proposed as a forensic investigation method. This systematic review is aimed to systematize evidence and peer-reviewed opinions reported during the first two years of pandemic, to evaluate the role of PMCT during the COVID-19 pandemic.

Materials and methods

An online literature search was performed to identify publications on PMCT during the COVID-19 pandemic between December 2019 and March 2022. For each publication included, the following data were collected: title and abstract, year of publication, type of article, number and type of individuals examined. The selected publications were also categorized based on PMCT findings, histopathological results, the comparison between PMCT and histopathological findings, cause of death and proposed role of PMCT during the pandemic.

Results

A total of 20 publications were included, mostly case reports (9/20). All cases examined included adults. The most frequent PMCT pattern in positive cases was diffuse mixed densities with prevalence of consolidations (pattern 1) (54%). In 97% of the cases where a comparison between PMCT and histological results was performed, a correspondence was found. In 82% of the cases the principal cause of death was COVID-19 pneumonia. PMCT has been proposed as a pre-autopsy screening tool in 62%, and as a method for augmenting post-mortem data in 50% of the papers reporting this issue.

Conclusion

This systematic review suggests that PMCT should be regarded as a highly valuable investigative technique for the forensic evaluation of deaths with ascertained or suspected COVID-19 pneumonia.

Potentials of post-mortem CT investigations during SARS-COV-2 pandemic: a narrative review

In December 2019, a new coronavirus, SARS-COV-2, caused a cluster of cases of pneumonia in China, and rapidly spread across the globe. It was declared a pandemic by the World Health Organization on March 11th, 2020. Virtual autopsy by post-mortem CT (PMCT) and its ancillary techniques are currently applied in post-mortem examinations as minimally or non-invasive techniques with promising results. In this narrative review, we speculate on the potentials of PMCT and its ancillary techniques, as a viable investigation technique for analysis of suspected or confirmed SARS-COV-2 deaths. An online literature search was performed by using three prefix search terms (postmortem, post-mortem, post mortem) individually combined with the suffix radiology, imaging, computed tomography, CT and with the search terms ‘SARS-CoV-2’ and ‘COVID-19’ to identify papers about PMCT and its ancillary techniques in SARS-COV-2 positive cadavers. PMCT findings suggestive for pulmonary COVID-19 in deceased positive SARS-COV-2 infection are reported in the literature. PMCT ancillary techniques were never applied in such cases. PMCT imaging of the lungs has been proposed as a pre-autopsy screening method for SARS-COV-2 infection. Further studies are needed to ascertain the value of PMCT in determining COVID-19 as the cause of death without autopsy histopathological confirmation. We advocate the application of PMCT techniques in the study of ascertained or suspected SARS-COV-2 infected deceased individuals as a screening technique and as a method of post-mortem investigation, to augment the numbers of case examined and significantly reducing infection risk for the operators.

Postmortem CT pulmonary findings in SARS-CoV-2-positive cases: correlation with lung histopathological findings and autopsy results

Introduction/purpose

Postmortem computed tomography (PMCT) is a valuable tool for analyzing the death of patients with SARS-CoV-2 infection. The purpose of this study was to investigate the correlation between PMCT lung findings in autopsy cadavers positive for SARS-CoV-2 infection and the severity of COVID-19 lung disease by histopathological analysis.

Materials and methods

We reviewed chest PMCT findings, paying particular attention to the lung parenchyma, in 8 autopsy cases positive for SARS-CoV-2. Correlations between chest PMCT and histopathological findings were assessed. Clinical conditions and comorbidities were also recorded and discussed. The primary cause of death was finally considered.

Results

In 6/8 cases, pulmonary PMCT findings were massive consolidation (4/8) and bilateral diffuse mixed densities with a crazy-paving pattern (2/8). These cases showed severe pulmonary signs of COVID-19 at histopathological analysis. In the remaining 2/8 cases, pulmonary PMCT findings were scant antideclive ground-glass opacities in prevalent gradient densities attributed to hypostasis. In 4/8 cases with massive consolidations, important comorbidities were noted. In 6/8 cases with severe pulmonary histopathological signs of lung COVID-19, autopsy found that the cause of death was cardiorespiratory failure. In the remaining 2/8 cases, histopathological analysis revealed lung alterations due to edema and some signs of SARS-CoV-2 infection; the cause of death was not attributed to SARS-CoV-2 infection (Table 1).

Discussion and conclusion

Chest PMCT findings correlate with the severity of COVID-19 lung disease at histopathology examination. According to our results, there may also be a relationship between cause of death and PMCT findings in COVID-19, which must be critically analyzed considering clinical antemortem data.

Virtual Autopsy in COVID19 Positive Sudden Death of a Young Adult Male; A Forensic Case Report

COVID-19 pandemic has changed the way medical professionals worked earlier. Every branch of medicine has revised its protocols to minimize transmission of infection among healthcare workers, and the branch of forensic pathology is no different. Conventional autopsies are generally not recommended in COVID cases as they pose the risk of transmission due to aerosol-generating procedures. However, there have been more than one occasion where the above recommendation has created ethical dilemmas in medicolegal autopsies. To the best of the author’s knowledge, this is the first known case of COVID-19 sudden death being investigated through a virtual autopsy in the Indian setting. The case further strengthens the notion of the virtual autopsy being sufficient in demonstrating the relevant findings for the purpose of the cause of death in a certain category of medicolegal cases.

Post-mortem computer tomography in ten cases of death while diving: a retrospective evaluation

INTRODUCTION

Self-contained underwater breathing apparatus (SCUBA) diving deaths have always been a challenge for forensic pathologists. Post-mortem computer tomography (PMCT) allows intracorporeal gas visualization, contributing to identify the cases in which the cause of death is arterial gas embolism (AGE). However, in the literature, it is indicated to perform the radiological examination within 24 h after death.

MATERIALS AND METHODS

In this retrospective study, 32 cases of death who had undergone PMCT 24-48 h after death/corpse finding between January 2011 and March 2021 were analyzed, including ten cases of SCUBA divers who died of AGE. All cases' radiological images were reviewed to localize the intracorporeal gas distribution alongside other findings that are usually related to SCUBA diving death. A semi-quantitative evaluation was also performed.

RESULTS

Most of the divers showed gas within the left heart and the arteries. In addition, the semi-quantitative evaluation revealed that the divers presented a higher mean amount of intraarterial gas compared to the fresh corpses. On the other hand, the putrefied corpses presented gas within the portal system and generalized subcutaneous emphysema with higher frequency and quantity than the divers and fresh corpses.

CONCLUSION

Our cases suggested that the PMCT, even when performed 24-48 h after death, remains a valuable tool to diagnose AGE in cases of SCUBA diving deaths. In addition, with the limit of the small sample size, our data showed that at least a medium quantity of intraarterial gas, when not associated with a high amount of gas within the portal system and subcutaneous emphysema, could be considered a diagnostic criterion of AGE.

Strengths and Weaknesses of Non-enhanced and Contrast-enhanced Cadaver Computed Tomography Scans in the Teaching of Gross Anatomy in an Integrated Curriculum

Cadaver-specific postmortem computed tomography (PMCT) has become an integral part in anatomy teaching at several universities. Recently, the feasibility of contrast-enhanced (CE)-PMCT has been demonstrated. The purpose of this study was to identify particular strengths and weaknesses of both non-enhanced and contrast-enhanced PMCT compared to conventional cadaver dissection. First, the students' perception of the learning effectiveness of the three different modalities have been assessed using a 34-item survey (five-point Likert scale) covering all anatomy course modules. Results were compared using the nonparametric Friedman Test. Second, the most frequent artifacts in cadaver CT scans, were systematically analyzed in 122 PMCT and 31 CE-PMCT data sets to quantify method-related limitations and characteristics. Perfusion quality was assessed in 57 vascular segments (38 arterial and 19 venous). The survey was answered by n = 257/320 (80.3%) students. Increased learning benefits of PMCT/ CE-PMCT compared to cadaver dissection were found in osteology (2/3 categories, P < 0.001), head and neck (2/5 categories, P < 0.01), and brain anatomy (3/3 categories, P < 0.01). Contrast-enhanced-PMCT was perceived particularly useful in learning vascular anatomy (10/10 categories, P < 0.01). Cadaver dissection received significantly higher scores compared to PMCT and CE-PMCT in all categories of the abdomen and thorax (7/7 categories, P < 0.001), as well as the majority of muscular anatomy (5/6 categories, P < 0.001). Frequent postmortem artifacts (total n = 28, native-phase n = 21, contrast injection-related n = 7) were identified and assessed. The results of this work contribute to the understanding of the value of integrating cadaver-specific PMCT in anatomy teaching.

Technical and interpretive pitfalls of postmortem CT: Five examples of errors revealed by autopsy

Image acquisition of dead bodies, particularly using postmortem computed tomography (PMCT), has become common in forensic investigations worldwide. Meanwhile, in countries such as Japan which have an extremely low rate of autopsy, PMCT is being increasingly used in the clinical field to certify the cause of death (COD) without performing an autopsy or toxicological tests, even in cases of unnatural death. Additionally, these PMCT images are predominantly interpreted by clinical personnel such as emergency physicians or clinicians who are not trained in PMCT interpretation and who work for the police, that is, the so-called police doctors. Many potential pitfalls associated with the use of PMCT have been previously described in textbooks and published papers, including the pitfalls of not performing a complete forensic pathology investigation, and the use of physicians without appropriate PMCT training to interpret PMCT and direct death investigation and certification. We describe five examples in which apparent misdiagnosis of COD based on PMCT misinterpretation was revealed by autopsy. Here are the five examples of errors: (1) Postmortem changes were misinterpreted as COD, (2) resuscitation effects were misinterpreted as COD, (3) COD was determined after an incomplete examination, (4) fatal findings caused by external origin were wrongly interpreted as 'of internal origin' based on PMCT, and (5) non-fatal findings on PMCT were wrongly interpreted as fatal. Interpretation of PMCT by appropriately trained physicians and an accompanying complete forensic investigation, including autopsy when indicated, is necessary to prevent significant errors in COD determination and related potential adverse medicolegal consequences.

Multidisciplinary Approach to Suspected Sudden Death Caused by Arteriovenous Malformation Rupture: A Case Report

Arteriovenous malformations (AVMs) are rare congenital conditions with a prevalence of less than 1% and are mostly asymptomatic. However, these malformations can suddenly cause intense pain or bleeding, leading to life-threatening medical problems. This report presents a case of an unexpected death in a 37-year-old previously healthy woman due to an intra-cerebellum arteriovenous malformation rupture identified during autopsy. While infective processes where preliminarily excluded, a Post Mortem Computed Tomography (PMCT) identified a tetra ventricular hemorrhage and intra-cerebellum hemorrhage. Toxicological examination was negative for most substances of abuse. During autopsy an intense hemorrhagic infiltrate in the subarachnoid space was observed. After formalin fixation of the brain the cerebellum showed hemorrhagic infarction on fourth ventricle sides, as well as several small reddish infarctions across the entire cerebellum parenchyma. Histological examination of the brain and cerebellum showed a suffusion of erythrocytes in the sub-arachnoid region. Evidence of an arterio-venous malformation, with several intertwine vessels of variable diameter, surrounded by hemorrhagic evidence. The autopsy played a crucial role in identifying the location and the possibly affected vessel, as well as defining the cause of death. It is necessary to have a greater number of autopsies to make an epidemiological contribution. Furthermore, it is crucial to create a multicenter data network with other authors from other departments to improve information about epidemiological, clinical, diagnostic and therapeutic data. Most brain AVMs as cause of death are often undiscovered.

Post-mortem CT lung findings at a medicolegal institute in SARS-CoV-2 RT-PCR positive cases with autopsy correlation

CoVID-19 is a novel viral infection with now well-established clinical radiological findings. There is limited data on post-mortem imaging. We explore the proposition that PMCT could be used as screening test. In an 11-week period, 39 deceased persons were referred for medicolegal investigation with pre-existing or subsequent nasopharyngeal swabs showing positivity on SARS-CoV-2 RT-PCR testing. All 39 had routine whole-body CT scans on admission and 12 underwent medicolegal autopsy. These cases were contrasted with 4 others which were negative on nasopharyngeal swabs despite PMCT findings suggestive of CoVID-19 pneumonia (designated false positive). Nine of the 12 autopsies showed lung histology consistent with those reported in CoVID-19 pneumonia. Typical clinical CoVID-19 lung findings on PMCT were only detected in 5 (42%). In 3 of the 4 false positive cases, lung findings showed non-COVID-19 histology but in 1, findings were identical. PMCT CoVID-19 findings in the lungs are therefore not specific and may not be detected in all cases due to obscuration by expected agonal CT findings or other pathologies that pre-dated SARS-CoV-2 infection. PMCT findings may otherwise be subtle. Although PMCT may hint at CoVID-19, we believe that nasopharyngeal swabs are still required for definitive diagnosis. Even with positive swabs, clinical CoVID-19 lung findings on PMCT are often not detected. PMCT findings can be subtle, extreme or obscured by agonal changes. Given this range of PMCT changes, the challenge for pathologists is to determine whether death has been caused by, or merely associated with, SARS-CoV-2 infection.

Use of post-mortem chest computed tomography in Covid-19 pneumonia

Background and aim

COVID-19 is an extremely challenging disease, both from a clinical and forensic point of view, and performing autopsies of COVID-19 deceased requires adequately equipped sectorial rooms and exposes health professionals to the risk of contagion. Among one of the categories that are most affected by SARS-Cov-2 infection are the elderly residents. Despite the need for prompt diagnoses, which are essential to implement all isolation measures necessary to contain the infection spread, deceased subjects in long-term care facilities are still are often diagnosed post-mortem. In this context, our study focuses on the use of post-mortem computed tomography for the diagnosis of COVID-19 infection, in conjunction with post-mortem swabs. The aim of this study was to assess the usefulness of post-mortem whole CT-scanning in identifying COVID-19 pneumonia as a cause of death, by comparing chest CT-findings of confirmed COVID-19 fatalities to control cases.

Materials and methods

The study included 24 deceased subjects: 13 subjects coming from long-term care facility and 11 subjects died at home. Whole body CT scans were performed within 48 h from death in all subjects to evaluate the presence and distribution of pulmonary abnormalities typical of COVID-19-pneumonia, including: ground-glass opacities (GGO), consolidation, and pleural effusion to confirm the post-mortem diagnosis.

Results

Whole-body CT scans was feasible and allowed a complete diagnosis in all subjects. In 9 (69%) of the 13 cases from long-term care facility the cause of death was severe COVID 19 pneumonia, while GGO were present in 100% of the study population.

Conclusion

In the context of rapidly escalating COVID-19 outbreaks, given that laboratory tests for the novel coronavirus is time-consuming and can be falsely negative, the post-mortem CT can be considered as a reliable and safe modality to confirm COVID-19 pneumonia. This is especially true for specific postmortem chest CT-findings that are rather characteristic of COVID-19 fatalities.

Postmortem radiologic and pathologic findings in COVID-19: The Toronto experience with pre-hospitalization deaths in the community

Over a year after the initial emergence of the disease, the COVID-19 pandemic continues to strain healthcare systems worldwide. The value of feedback and connection between clinical care, public health, and death investigation systems has never been more clear. To this end, knowledge of the radiologic and histopathologic features of fatal COVID-19 is critical for those working with the living and the dead. Most of the medical descriptions of COVID-19 are either focused on clinical in vivo medical imaging or autopsies performed following an intensive course of treatment over days to weeks prior to death, rather than deaths in the community prior to hospitalization. Here we report the postmortem computed tomography (PMCT) and lung histopathology in five fatal cases of COVID-19 that were subject to medicolegal death investigation. All individuals died in the community without medical treatment, or after a brief terminal admission to hospital. In these cases, the main PMCT findings included: diffuse lung changes including ground glass-type opacifications, a “crazy paving” appearance, variable areas of more dense consolidation, and relatively few areas of spared/less involved lung parenchyma. The unifying histopathology was diffuse alveolar damage in various stages of cellular evolution. In all cases, the pattern of PMCT and the lung histopathology corroborated the diagnosis of COVID-19. We propose the routine use of PMCT as a potential screening tool for the identification of COVID-19 related fatalities in the medicolegal setting where a paucity of historical information may not otherwise permit the identification of this disease prior to autopsy.

Postmortem CT lung findings in decedents with Covid-19: A review of 14 decedents and potential triage implications

Objective

Materials and methods

Results

Conclusion

Ventilated postmortem computed tomography to evaluate the lungs of dogs with and without focal lung lesions

OBJECTIVE

To identify the optimal ventilation pressure for ventilated postmortem CT assessment of the lungs in cadaveric dogs and compare the optimal ventilation pressures between dogs with and without focal lung lesions.

SAMPLE

12 cadaveric dogs.

PROCEDURES

CT was performed with dogs positioned in sternal recumbency within 30 to 180 minutes after death. After orotracheal intubation, lungs were aerated to ventilation pressures of 0, 10, 15, 20, 25, 30, and 35 cm H₂O. Lung attenuation measurements were made at 5 predetermined anatomical locations with use of a multi-image analysis graphic user interface tool. Lungs were considered hyperaerated (-1000 to -901 HU), normo-aerated (-900 to -501 HU), poorly aerated (-500 to -101 HU), and nonaerated (-100 to 100 HU) on the basis of lung attenuation values. Optimal ventilation pressure was defined as the pressure at which the percentage of normo-aerated lung was greatest. For analysis, dogs were assigned to one group when focal lung lesions were evident and to another group when lesions were not evident.

RESULTS

Median optimal ventilation pressure was significantly higher for those dogs with lung lesions (35 cm H₂O), compared with those without (25 cm H₂O).

CONCLUSIONS AND CLINICAL RELEVANCE

A ventilation pressure of 35 cm H₂O may be considered for ventilated postmortem CT to determine the presence of focal lung lesions; however, further investigation is required.

[Postmortem imaging of the lung in cases of COVID-19 deaths]

CLINICAL/METHODOLOGICAL ISSUE

COVID-19 is a new viral disease that is associated with inflammatory pulmonary changes which can be detected in computed tomography (CT). So far postmortem CT (PMCT) has not been used as a screening instrument for the evaluation of deaths with and without autopsy. In this respect, its validity has to be proved in comparison to clinical-radiological experiences.

STANDARD RADIOLOGICAL METHODS

Postmortem CT METHODICAL INNOVATIONS: So far, PMCT can be regarded as a methodological innovation that has not yet been sufficiently evaluated for pneumonia.

PERFORMANCE

CT in clinical routine has a high sensitivity for pneumonia. However, to what extent postmortem artifacts are relevant to PMCT still has to be determined.

ACHIEVEMENTS

There is still no standard procedure for the postmortem radiological diagnosis of COVID-19 disease. Despite postmortem artifacts, PMCT can provide valuable information about the presence of pneumonia with interstitial character, especially without autopsy.

PRACTICAL RECOMMENDATIONS

PMCT is particularly useful in the assessment of suspected cases of COVID-19 pneumonia for morphological assessment in the context of monitoring deaths in the current pandemic situation.

Complete post-mortem data in a fatal case of COVID-19: clinical, radiological and pathological correlations

A 75-year-old man presented to a French hospital with a 4-day fever after returning from a coronavirus disease-19 (COVID-19) cluster region. A reverse-transcription polymerase chain reaction test was positive for severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) using a nasopharyngeal swab sample. After he returned home and a telephone follow-up, he was found deceased 9 days after first showing symptoms. Whole-body, non-enhanced, post-mortem computed tomography (PMCT) and a forensic autopsy were performed approximately 48 h after death, with sanitary precautions. The PMCT showed bilateral and diffuse crazy-paving lung opacities, with bilateral pleural effusions. Post-mortem virology studies detected the presence of SARS-CoV-2 (B.1 lineage) in the nasopharynx, plasma, lung biopsies, pleural effusion and faeces confirming the persistence of viral ribonucleic acid 48 h after death. Microscopic examination showed that severe lung damage was responsible for his death. The main abnormality was diffuse alveolar damage, associated with different stages of inflammation and fibrosis. This case is one of the first to describe complete post-mortem data for a COVID-19 death and highlights the ability of PMCT to detect severe involvement of the lungs before autopsy in an apparently natural death. The present pathology results are concordant with previously reported findings and reinforce the disease pathogenesis hypothesis of combined viral replication with an inappropriate immune response.

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.

Lung density measurement in postmortem computed tomography: a new tool to assess immediate neonatal breath in suspected neonaticides

INTRO

Evidence of breath after birth is one of the main forensic issues in suspected neonaticide. Hydrostatic test (HT) and pathological examination are currently used to assess it, but they are not entirely reliable or immediately available.

OBJECTIVE

To determine the performance of postmortem computed tomography (PMCT) to assess neonatal breath in suspected neonaticide, by comparing lung CT attenuation values between live birth and stillbirth cases, in correlation with HT and pathology.

METHOD

Cases of suspected neonaticides who underwent a PMCT and complete forensic autopsy with an HT were retrospectively selected from the databases of four French Forensic Medicine Departments. The diagnosis of vitality (i.e., stillbirth or live birth) was based on the pathological examination and/or a combination of arguments, including HT result. Lung density on CT was measured in Hounsfield units (HU) by ROIs drawn in both pulmonary parenchymas.

RESULTS

Eleven patients were included, six live birth and five stillbirth cases. The result of HT was concordant with pathological examination when available (seven cases). Mean lung densities in live birth cases (- 173 HU [- 255; - 91 CI 95%]) were significantly lower than in stillbirth cases (40 HU [28; 52 CI 95%]) (p < 0.05), with a very high degree of interobserver reproducibility (ICC = 0.998 (CI 95% 0.991-0.999; p < 0.001).

CONCLUSION

PMCT and especially lung CT attenuation measurement is a reliable and easy-to-use method for assessing neonatal breath in suspected neonaticides.

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.