COVID-19. Imaging features of a fatal case.

An 81-year-old male arrived at the emergency because of ten days dry cough and fever treated by Acetaminophen.  His body temperature was 38.2°C and SpO2 was 89% on FiO2 21%. Lymphocytopenia (0.76x 103/ul; normal range 1.5-3.0 ), neutrophilia (10.85 x10/ul; normal range 3.0-5.8), increased of PCR (236.5mg/l; normal range 0-5), and increased D-dimer concentration 22.27mg/l (normal range 0-0.5), Fibrinogen (596mg/dl normal range 180-400) and LDH (807U/L normal range 125-220) was detected. Based on the COVID-19 outbreak, a nasopharyngeal swab was performed, with a positive result for SARS-CoV-2 on real-time reverse transcriptase-polymerase chain reaction assay.  The diagnosis of viral pneumonia based on nucleic acid test results was available one day after CT and only supportive therapies had been applied before.

Despite antiviral treatments, antibiotics, hydroxychloroquine, thromboprophylaxis with enoxaparin and non-invasive ventilation, clinical conditions did not improve and laboratory parameters remained constantly altered (on the sixth-day lymphocytes were 0.72x 103/ul, neutrophiles 13.25x10/ul, PCR 183mg/l, LDH 520 U/L.

The patient died after ten days, due to acute respiratory failure in multi-organ failure, two days after follow-up TC.

This case highlights that early aggressive treatment could change the prognosis of these patients because when the patient was admitted he already had an advanced stage of the disease.

Unenhanced chest CT showed at the admission bilaterally evidence of widespread thickening of the pulmonary interstices, more marked in the lower lobes, especially in the posterior segments and in the posterior segments and in the concomitance of the pleural sheets. There is moderate concomitant segmental thickening of the pleural leaflets in contiguity with the parenchymal opacities.

On the seventh-day unenhanced chest CT showed widespread thickening of the lung interstices, with the presence of ground-glass areas, involving larger areas of parenchyma and engaging all the lung lobes. Onset of widespread areas of parenchymal consolidation, wider at the lower lobes, with prevailing posterior arrangement, in contiguousness of the pleura could be also seen.

The ongoing pandemic of Coronavirus disease 2019 (COVID-19) is severely challenging healthcare systems all around the world, with the need to provide intensive care to a previously inconceivable number of patients (Wu Z, 2020). When SARS-CoV-2 infects a person, the lesions are not limited to the lungs. The virus causes viraemia after entering the body and the main clinical manifestations are fever, pharyngalgia, fatigue, diarrhoea and other non-specific symptoms. The incubation takes 1-14 days. Peripheral blood leucocytes are normal or slightly lower at this phase. Then the viruses spread through the bloodstream and mainly in the lungs, gastrointestinal tract, heart. This phase occurs around 7-14 after the onset of the symptoms when the virus starts a second attack, which is also the main cause of the aggravation of symptoms. As this time, pulmonary lesions become worse, and chest CT scans show imaging changes consistent with COVID-19. At this stage, the peripheral blood lymphocytes decrease significantly, and inflammatory factors in peripheral blood are increased. Patients at this phase will begin to develop the hypercoagulable state and D-Dimer increases from mild to significant, with prolonged prothrombin time (PT) and gradual decrease of fibrinogen and platelet (Taisheng Li, 2020).

Imaging features: COVID-19 imaging mainly has subpleural distribution and is confined to the middle and lower zones on the initial chest CT. Follow up CT shows that, as the disease advances, consolidates and pervades the lungs. Also, the upper lobes are affected (Yan L. 2020)

 Unenhanced chest CT shows bilateral disease in 89.3% with a ground-glass pattern in 53.8% and ground glass with consolidation in 46.2% (JWu et al 2020); interlobular septal thickening in 75% (Song F et al 2020); air bronchogram in 80% (Song F, 2020). An increased lung involvement score is a powerful prognostic indicator (Ran Yang, 2020).

Thoracic lymphadenopathy is generally absent and pleural effusion is extremely rare. (Bernheim A et al 2020)