Chest CT imaging features of COVID-19 pneumonia: First radiological insights from Porto, Portugal

A Carvalho; R Cunha; B A Lima; J M Pereira; A J Madureira

doi:10.1016/j.ejro.2020.100294

Chest CT imaging features of COVID-19 pneumonia: First radiological insights from Porto, Portugal

Eur J Radiol Open. 2020:7:100294. doi: 10.1016/j.ejro.2020.100294. Epub 2020 Nov 28.

Authors

A Carvalho¹, R Cunha¹, B A Lima², J M Pereira¹, A J Madureira¹

Affiliations

¹ Serviço de Radiologia, Centro Hospitalar Universitário de São João, EPE, Portugal.
² Oficina de Bioestatística, Portugal.

Abstract

Introduction: The outbreak of a highly infectious respiratory disease - COVID-19 - has spread globally and a novel type of coronavirus (SARS-CoV-2) was identified as its cause. Chest CT findings have been described as an aid for COVID-19 diagnosis and management. We aimed to describe the CT imaging characteristics in a group of COVID-19 patients while we also intended to assess if any of these radiological features were associated with short-term prognosis.

Materials and methods: CT examinations from 164 consecutive patients with at least one positive RT-PCR nucleic acid assay for SARS-CoV-2 were retrospectively analyzed. Numerous CT imaging features were recorded independently by two radiologists. Patients were grouped according to their status 14 days after the initial CT scan in either discharged/hospitalized in a non-ICU ward (favorable prognosis group) versus deceased/admitted to an intensive care unit (unfavorable prognosis group).

Results: Ground-glass opacities (89.0 %) and consolidations (73.2 %) with multilobar involvement were the predominant imaging findings, while a nodular pattern (3.7 %) and cavitation (1.2 %) were uncommon. Mean age was higher in the mortality/ICU group. Ground-glass opacities and consolidations were dominant in both groups, but distribution pattern of abnormalities was different, being more often diffuse in the mortality/ICU group. Linear opacities and opacities that were rounded in shape were more frequently observed in the favorable prognosis group. CT severity index was significantly higher in the mortality/ICU group. For assessing unfavorable prognosis, the best cut-off for CT severity index was 24 (sensitivity 78 %; specificity 59 %). Interobserver agreement for all CT findings was excellent.

Conclusion: COVID-19 pneumonia in Porto, Portugal, manifests as multilobar ground-glass opacities and consolidations. Older age, diffuse distribution and increasing CT severity index are associated with worse short-term prognosis while linear opacities resembling organizing pneumonia and rounded opacities herald a more favorable prognosis.

Keywords: COVID-19; Chest; Computed tomography; SARS-CoV-2.