Introduction
Coronavirus disease (COVID-19) has been spreading worldwide since
December 2019 from Wuhan, Hubei Province.1 The virus
called SARS-Cov-2 belongs to the Betacoronavirus genus, is composed of a
positive single-stranded RNA, and has a 50-200 nm
diameter.2,3 Bats are the natural reservoir for
coronaviruses.4 On April 26th 2020,
more than 2 355 853 cases (of which 947 693 in Europe) and 164 656
deaths worldwide were reported due to this pandemic.5On March 16th 2020 in France, 124 114 cases were
confirmed with 22 614 deaths (i.e. 18,6 % of
mortality).6 Fever, cough, fatigue, diarrhoea,
dyspnoea and myalgia are the most common symptoms but the patients’
condition can deteriorate rapidly, requiring intensive medical
care.7,8Real time reverse-transcription polymerase chain reaction (RT-PCR) is
the standard reference to detect viral nucleic acid but false-negative
results have been reported and have led to a 66-80 % sensitivity due to
multiple factors, notably the quality of sampling.9Compared to RT-PCR, chest computed tomography (CT) is an easy-to-use and
a faster method to diagnose and assess an early pulmonary COVID-19
infection.10 Chest CT can also help to monitor the
evolution and diagnose complications of COVID-19. Indeed, some authors
have demonstrated the diagnostic value of chest CT in COVID-19 pneumonia
describing compatible radiological signs.11–13 Ai.et al. have evaluated chest CT diagnostic value in 1014 cases of
suspected COVID-19 using RT-PCR as a reference, and determined a
sensitivity of 97 % and negative predictive value of 83
%.10 Few authors have studied the prognostic value of
chest CT. Yuan et al . have found in a small sample of 27 patients
(of which 10 died) higher rates of consolidation and air bronchogram in
the dead patients’ group.14 In a retrospective study,
Zhao et al. found pleural effusions and architectural distorsions
to be CT signs potentially correlated with severe deterioration in a
small population of severe or deceased patients (14/101
patients).15
In this study, our main objective was to assess whether some chest CT
signs were associated with pejorative evolution (defined as requiring
intensive care unit hospitalization, invasive endotracheal ventilation
or a fatal outcome), for patients with COVID-19. Our secondary objective
was to evaluate the diagnostic value of chest CT versus RT-PCR.