Chest Radiographic and CT Findings of the 2019 Novel Coronavirus Disease (COVID-19): Analysis of Nine Patients Treated in Korea

Abstract

Objective: This study presents a preliminary report on the chest radiographic and computed tomography (CT) findings of the 2019 novel coronavirus disease (COVID-19) pneumonia in Korea.

Materials and methods: As part of a multi-institutional collaboration coordinated by the Korean Society of Thoracic Radiology, we collected nine patients with COVID-19 infections who had undergone chest radiography and CT scans. We analyzed the radiographic and CT findings of COVID-19 pneumonia at baseline. Fisher's exact test was used to compare CT findings depending on the shape of pulmonary lesions.

Results: Three of the nine patients (33.3%) had parenchymal abnormalities detected by chest radiography, and most of the abnormalities were peripheral consolidations. Chest CT images showed bilateral involvement in eight of the nine patients, and a unilobar reversed halo sign in the other patient. In total, 77 pulmonary lesions were found, including patchy lesions (39%), large confluent lesions (13%), and small nodular lesions (48%). The peripheral and posterior lung fields were involved in 78% and 67% of the lesions, respectively. The lesions were typically ill-defined and were composed of mixed ground-glass opacities and consolidation or pure ground-glass opacities. Patchy to confluent lesions were primarily distributed in the lower lobes (p = 0.040) and along the pleura (p < 0.001), whereas nodular lesions were primarily distributed along the bronchovascular bundles (p = 0.006).

Conclusion: COVID-19 pneumonia in Korea primarily manifested as pure to mixed ground-glass opacities with a patchy to confluent or nodular shape in the bilateral peripheral posterior lungs. A considerable proportion of patients with COVID-19 pneumonia had normal chest radiographs.

Keywords: COVID-19; Chest X-ray; Computed tomography; Coronavirus; Pneumonia.

Fig. 1. Representative chest radiographic (A) and CT images (B, C) of COVID-19 pneumonia manifesting as confluent mixed ground-glass opacities and consolidation on CT.

A. Anteroposterior chest radiograph shows multifocal patchy peripheral consolidations in bilateral lungs, except for left upper lung zone. B, C. Coronal and axial chest CT images show confluent mixed ground-glass opacities and consolidative lesions in peripheral bilateral lungs. Discrete patchy consolidation (arrowheads) is noted in left upper lobe. On axial CT image (C), confluent lesions are mainly distributed in peripheral lung along bronchovascular bundles. Most of lesions spare juxtapleural area, and minor proportion of lesions touch pleura. Lesions contain multiple air-bronchograms, and air-bronchogram in superior segment of right lower lobe is distorted (arrows). COVID-19 = Coronavirus disease 2019, CT = computed tomography

Fig. 2. Representative chest radiographic (A) and CT images (B, C) of COVID-19 pneumonia manifesting as confluent pure ground-glass opacities on CT.

A. Baseline anteroposterior chest radiograph shows patchy ground-glass opacities in right upper and lower lung zones and patchy consolidation in left middle to lower lung zones. Several calcified granulomas are incidentally noted in left upper lung zone. B, C. Baseline axial and coronal chest CT images show confluent pure ground-glass opacities involving both lungs. Most of confluent and patchy ground-glass opacities about pleura and fissure in peripheral lung. A few calcified granulomas are incidentally noted in left upper lobe.

Fig. 3. Representative chest radiographic (A) and CT images (B) of COVID-19 pneumonia manifesting as single nodular lesion.

A. Anteroposterior chest radiograph shows single nodular consolidation (arrows) in left lower lung zone. B. Coronal chest CT image taken on same day shows 2.3-cm ill-defined nodular lesion with reversed halo sign with thick rim in left lower lobe, abutting adjacent pleura.

Fig. 4. Representative CT images (A, B) of COVID-19 pneumonia manifesting as radiograph-negative multiple patchy to nodular mixed ground-glass opacities and consolidations.

A. Axial chest CT image shows ill-defined mixed ground-glass opacities and consolidative lesions with patchy and elongated shape (arrows) touching pleura in superior segment of right lower lobe. B. Axial chest CT image shows ill-defined part-solid nodules (arrows; mixed ground-glass opacities and solid nodules) along bronchovascular bundles in posterior segment of right upper lobe.