Chest X-ray features of SARS-CoV-2 in the emergency department: a multicenter experience from northern Italian hospitals

Abstract

Objectives: To evaluate the imaging features of routine admission chest X-ray in patients referred for novel Coronavirus 2019 infection.

Methods: All patients referred to the emergency departments, RT-PCR positive for SARS-CoV-2 infection were evaluated. Demographic and clinical data were recorded. Two radiologists (8 and 15 years of experience) reviewed all the X-ray images and evaluated the following findings: interstitial opacities, alveolar opacities (AO), AO associated with consolidation, consolidation and/or pleural effusion. We stratified patients in groups according to the time interval between symptoms onset (cut-off 5 days) and X-ray imaging and according to age (cut-off 60 years old). Computed tomography was performed in case of a discrepancy between clinical symptoms, laboratory and X-ray findings, and/or suspicion of complications.

Results: A total of 468 patients were tested positive for SARS-CoV-2. Lung lesions primarily manifested as interstitial opacities (71.7%) and AO opacities (60.5%), more frequently bilateral (64.5%) and with a peripheral predominance (62.5%). Patients admitted to the emergency radiology department after 5 days from symptoms onset, more frequently had interstitial and AO opacities, in comparison to those admitted within 5 days, and lung lesions were more frequently bilateral and peripheral. Older patients more frequently presented interstitial and AO opacities in comparison to younger ones. Sixty-eight patients underwent CT that principally showed the presence of ground-glass opacities and consolidations.

Conclusions: The most common X-ray pattern is multifocal and peripheral, associated with interstitial and alveolar opacities. Chest X-ray, compared to CT, can be considered a reliable diagnostic tool, especially in the Emergency setting.

Keywords: Coronavirus; Infections; Radiography; Tomography; X-ray computed.

Fig. 1

Representative chest radiographic of SARS-CoV-2 pneumonia in a 56-year-old man (A) and a 61-year-old man (B) manifesting as multiple bilateral and symmetric linear interstitial opacities involving the perihilar and the peripheral zones in both of cases. No pleural effusion or consolidative lesions are evident.

Fig. 2

Representative chest radiographic of SARS-CoV-2 pneumonia manifesting as consolidations. A. 71-year-old man. Anteroposterior chest radiograph shows multiple lung consolidations with typical bilateral and symmetric aspect in the middle and low part of both lungs involving the peripheral zones. B. 68-year-old man. Anteroposterior chest radiograph shows in the peripheral zone of both lungs multiple consolidations with the same appearance involving the middle and the inferior part of both lungs.

Fig. 3

Representative chest radiographic of SARS-CoV-2 pneumonia manifesting as confluent mixed alveolar and linear opacities. Anteroposterior chest radiograph shows multifocal alveolar opacities and linear interstitial opacities in both lungs.

Fig. 4

Comparison between chest X-ray (A) and CT findings (B, C, D). Chest X-ray shows slightly linear opacities in the lower portion of the right lung. CT axial images (B and C in the axial plane, D in the coronal plane) with window width and level for the evaluation of lung parenchyma allow us to correctly found out the presence of multiple bilateral ground-glass opacities, especially in the subpleural space.

Fig. 5

Comparison between chest X-ray (A) and CT findings (B, C, D). Chest X-ray shows the presence of multiple confluent mixed alveolar and linear opacities, distributed bilaterally. CT axial images (B and C in the axial plane, D in the coronal plane) with window width and level for the evaluation of lung parenchyma allow to correctly found out the presence of multiple and confluent GGOs, distributed in particular in the right lung, especially in the subpleural area.