Role of PMCT as a triage tool between external inspection and full autopsy – Case series and review

Knowledge and attitudes of Polish prosecutors and general Polish population in regard to post-mortem computed tomography in 2019

Post-mortem computer tomography (PMCT) is an imaging technique that is gaining popularity both worldwide and in Poland. It provides certain benefits in death investigation that a conventional autopsy is not able to, however, it has significant limitations. As PMCT and post-mortem computed angiography (PMCTA) continue to develop in this country, it is critical to become aware what people know and think about these imaging techniques, especially the prosecutors who officially order such examinations to be performed. In 2019, two concurrent surveys were administered to Polish prosecutors and general Polish population, respectively, regarding their current knowledge and opinions on PMCT. The results were collected both online and on paper, and then subjected to analysis. In total, 92 prosecutors and 227 non-prosecutors responded to the survey. The present authors observed that while prosecutors were more likely to have heard of this examination than the general public, their knowledge was often inadequate or incorrect. Conventional autopsy was still held as the gold standard in death investigation. However, a good popular sentiment towards PMCT was shown, and a desire to learn more about it - not just among prosecutors, but among the general public as well. The present authors' recommendation is that more courses and training should be organised for Polish prosecutors to compensate this knowledge gap.

Postmortem CT in decedents with SARS-CoV-2 infection. A single institution experience

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 produced a global pandemic with significant mortality. As autopsies are not routinely performed on all decedents with SARS-CoV-2 infection, postmortem CT (PMCT) may be valuable to provide additional information on the cause of death and risk factors known to be associated with an increased mortality in COVID-19. The purpose of this manuscript is to review the PMCT findings in a series of 42 decedents with SARS-CoV-2 infection from our institution. Retrospective analysis of 42 decedents who had a positive postmortem nasopharyngeal swab for SARS-CoV-2 and had a PMCT were included in this study. Images were reviewed for pulmonary findings seen in COVID-19 and other organ involvement. Of the 42 decedents, although the majority had imaging findings in the lungs that would be consistent with COVID-19 and acute respiratory distress syndrome, in 14% of the decedents the SARS-CoV-2 infection was likely coincidental and the PMCT findings suggested that they died from other pathology. Over half of the decedents that died from COVID-19 had PMCT findings of vascular disease. PMCT is useful to identify pulmonary and extra pulmonary findings in decedents with SARS-CoV-2 infection that can provide additional information, which may be useful for the forensic pathologist to help determine the underlying cause of death.

Supplemental data for this article are available online at

A review of visualization techniques of post-mortem computed tomography data for forensic death investigations

Postmortem computed tomography (PMCT) is a standard image modality used in forensic death investigations. Case- and audience-specific visualizations are vital for identifying relevant findings and communicating them appropriately. Different data types and visualization methods exist in 2D and 3D, and all of these types have specific applications. 2D visualizations are more suited for the radiological assessment of PMCT data because they allow the depiction of subtle details. 3D visualizations are better suited for creating visualizations for medical laypersons, such as state attorneys, because they maintain the anatomical context. Visualizations can be refined by using additional techniques, such as annotation or layering. Specialized methods such as 3D printing and virtual and augmented reality often require data conversion. The resulting data can also be used to combine PMCT data with other 3D data such as crime scene laser scans to create crime scene reconstructions. Knowledge of these techniques is essential for the successful handling of PMCT data in a forensic setting. In this review, we present an overview of current visualization techniques for PMCT.

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

Objective

Materials and methods

Results

Conclusion

The possibility of identifying brain hemorrhage in putrefied bodies with PMCT

This paper aims to demonstrate that post-mortem CT (PMCT) can locate intracranial hemorrhages, even in decomposed cases. This is of relevance in that post-mortem decomposition is particularly damaging to the brain tissue’s consistency, resulting in great difficulties to reliably diagnose and locate intracranial hemorrhages. We searched our case database of the last 11 years to find cases with decomposition of the body, where PMCT and an autopsy had been performed. We identified eleven cases according to these criteria. Postmortem interval ranged from 2 days to 2 weeks, and post-mortem radiological alteration index (RAI) was at or above 49. Eight out of eleven cases showed an intraparenchymal hemorrhage whereas the hemorrhage was extra-axial in the remaining three cases. Autopsy validated the presence of intracranial hemorrhage in all eleven cases, but location could not be confirmed due to liquid state of the brain. PMCT identified and localized intracranial hemorrhages in decomposed bodies, and in all of these cases, autopsy validated their presence. The actual cause of the hemorrhage (e.g. tumor, metastasis, vascular malformation, hypertensive hemorrhage) remained obscure. From this case series, it can be concluded that PMCT may add relevant information pertaining to localization of intracranial hemorrhages in decomposed bodies.

Implications for forensic death investigations from first Swiss post-mortem CT in a case of non-hospital treatment with COVID-19

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3D Visualisation of lung pathology allows to better estimate the distribution of aerated, poorly aerated and non-aerated lung regions

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Forensic COVID-19 autopsy apparently showing a different (higher) degree of pathology than hospital autopsy reports compared to SARS-COV-2, but on par with SARS.

Case details: A case of a 50-year old HIV-positive man is presented, with focus on visualization of post-mortem computed tomography (PMCT) of the lungs, in comparison to a forensic control case. He had been found dead at home, a day after his nasopharyngeal swab had returned positive for SARS-COV-2, three days after the sample had been taken as an outpatient, over five weeks after first exhibiting possible symptoms. 3D-visualization was performed by visually discriminating correlates for aerated, poorly aerated and non-aerated lung regions. The visual side-by-side comparison with a control case shows the deterioration beyond any ”normal” post-mortem finding, however. The PMCT findings in the lungs resemble those of patients with acute respiratory distress syndrome (ARDS), while histologically identified inflammation also shows, in part binuclear, lymphocytes. In addition, acute liver dystrophy and acute tubular necrosis in the kidneys were found. Except coronary artery atherosclerosis, there appeared to be no remarkable pathology of the heart.

Comment: With the pandemic impact of SARS-COV-2, a range of issues unfolds, also for medicolegal investigations into deaths, as we report the first Swiss case with post-mortem CT where death had occurred due to a SARS-COV-2 infection, with features of a severe acute respiratory distress syndrome, as an outpatient. As this pandemic from the view of risk assessment does constitute a black swan, underestimated fat tails as technical reason should be addressed by also analyzing apparent extreme single observations. This case of an outpatient (without hospital or intensive-care treatment) shows a pulmonary progression beyond the typical findings of COVID-19, to a non-specific picture of ARDS, where histologically, in part binuclear lymphocytes were remarked. What appeared to be an initially slow progression with final rapid escalation raises the question whether nasopharyngeal swabs alone or added pulmonary CT might be better for screening high-risk patients. The reported symptoms and relatively late medical consultation in this case appeared to contrast with the extensive pathology, raising the question whether any search for super-spreaders should not just focus on asymptomatic but under-reported symptomatic patients, and whether their prolonged circulation in everyday life would justify measures such as for example more extensive face mask policies. As post-mortem testing for SARS-COV-2 may not be available for every case, PMCT may provide sensitive testing for lung changes related to COVID-19. In order to allow for more precise medicolegal investigations in the context of COVID-19, however, any more specific extra tests may have to be financed by stakeholders in epidemiology, infectious disease or policy.

Left myocardial wall measurements on postmortem imaging compared to autopsy

PURPOSE

The aims of this study were, firstly, to determine the relationship of left ventricular wall thickness (LVWT) measurements between postmortem computed tomography (PMCT) and postmortem magnetic resonance imaging (PMMR) and, secondly, to assess the utility of postmortem imaging for LVWT measurements compared to autopsy.

MATERIALS AND METHODS

All cases ≥18years old, with postmortem interval ≤4days, cardiac PMCT, PMMR, and full forensic autopsy, were reviewed in our database retrospectively. Exclusion criteria were gas accumulations in the myocardial wall and cardiac trauma. LVWT on PMCT and PMMR was assessed. The measurements were repeated by the same rater after 2months. Autopsy reports were reviewed, and LVWT and pericardial fluid volume measured at autopsy were noted. Pericardial fluid volume >50ml was determined positive for pericardial effusion.

RESULTS

A total of 113 cases were included in the study. Twelve cases had pericardial effusion. Intrarater reliability for imaging based LVWT was excellent. LVWT (free wall) was significantly larger on PMCT (18.3mm) compared to PMMR (17.6mm), but these measurements correlated positively. LVWT (anterior wall) was significantly larger on PMMR (15mm) than at autopsy (14mm), and these measurements also correlated positively. Pericardial effusions led to larger differences between PMMR and autopsy measurements, however without statistical significance.

DISCUSSION

There exist discrepancies between LVWT as measured on postmortem imaging and at autopsy. Specialists should be aware in order to not misinterpret imaging measurements.

Approaching pulmonary fat embolism on postmortem computed tomography

PURPOSE

Pulmonary fat embolism (PFE) is a relevant diagnosis playing a role as a sign of vitality or a cause of death. Its severity is assessed according to histological grading systems like that of Falzi. The aim of this study was to determine the utility of unenhanced postmortem computed tomography (PMCT) for PFE diagnosis based on the detection of fat layers.

METHODS

Consecutive cases with PMCT and autopsy were studied retrospectively. The case group consisted of cases with positive PFE, and the control group included cases with negative PFE. Three observers independently assessed PMCT data for fat layers in the pulmonary trunk and the right and left pulmonary artery. For cases with fat layers, autopsy protocols were assessed for the cause of death, relation to trauma, and undertaken resuscitation measures.

RESULTS

Eight hundred thirty cases were included: 366 PFE positive cases (144 of Falzi grade 1, 63 of 1.5, 99 of 2, 28 of 2.5, and 32 of 3) and 464 PFE negative cases. Interrater reliabilities varied between substantial and almost perfect, and discrepancies were solved according to majority. Eighteen cases showed fat layers on PMCT (2 controls-traumatic instantaneous deaths-, 16 PFE positive cases). PMCT showed low sensitivity but high specificity for PFE diagnosis. The layers were located at the same position in the pulmonary trunk directly adjacent to the pulmonary valve distal to the right ventricle.

CONCLUSION

Fat layer on PMCT is a rare finding but relates to PFE diagnosis, especially of severe histological grade. It is to be expected in a typical position within the pulmonary trunk.