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

Abstract

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.

Keywords: Autopsy; COVID-19; Coronavirus; Pneumonia; Post mortem changes; Post mortem computed tomography.

Fig. 1

Typical PMCT COVID-19 infection appearance, with bilateral multiple areas of GGO (arrows), without gravitational dependency. Enlarged vessels within GGO areas can also be seen (arrowhead).

Fig. 2

In a case of PMCT typical GGO of COVID-19 infection in middle and lower right lobe (arrows) were associated to consolidation in lower lobe (arrowhead). The intermediate stage of the disease is characterized by an increase in the number and size of GGOs and a progressive transformation of GGO into multifocal consolidation.

Fig. 3

In PMCT of COVID-19 case we observed in the right lower lobe inter-and intralobular septal thickening (arrohead) superimposed to GGO areas (arrow): the so called “crazy-paving” pattern.

Fig. 4

PMCT in case of pneumonia unrelated to COVID-19 infection. Alveolar consolidation is observed in right lower lobe (arrowhead), surrounded by GGO (arrow). These findings are nonspecific and did not showed the typical distribution of COVID-19 infection.

Fig. 5

Increased pulmonary density with a horizontal border, typical for postmortem lung hypostasis, was observed in the dependent region of the bilateral lower lobes (arrowheads); typical GGO signs of COVID-19 infections (not showed) were founded in the same exam in upper lobes.

Fig. 6

PMCT in case of COVID-19 infection with diffuse and bilateral interstitial and alveolar involvement. CT findings in similar cases are not specific, as they can be seen in advanced stage of several infectious and non-infectious disease.

Fig. 7

Receiver Operating Curve (ROC) analysis of the post-mortem computed tomography (PMCT) score in comparison with the single findings. The area under the receiver operating characteristic curve (AUC-ROC) for the PMCT score showed a higher performance than the single PMCT features, demonstrating that PMCT has the potential for post-mortem imaging of lung involvement in COVID-19 infections.

Fig. 8

PMCT, in case with COVID-19 infection and congestive cardiac failure, showed in upper lobes GGO (arrow); bronchovascular bundle and interlobular septa thickening (arrowhead). Pleural effusion and cardiac chambers enlargement were also observed.