RadioGraphics Update: Radiographic and CT Features of Viral Pneumonia

Abstract

Editor's Note.-Articles in the RadioGraphics Update section provide current knowledge to supplement or update information found in full-length articles previously published in RadioGraphics. Authors of the previously published article provide a brief synopsis that emphasizes important new information such as technological advances, revised imaging protocols, new clinical guidelines involving imaging, or updated classification schemes. Articles in this section are published solely online and are linked to the original article.

Figure 1.

Mild cough and dizziness 1 day before visiting a screening clinic in a 62-year-old woman with contact history with a confirmed SARS-CoV-2–infected patient 4 days earlier. RT-PCR test results were positive for SARS-CoV-2, and she was transferred to our hospital and admitted to a containment zone. Initial chest CT findings (not shown) were normal. A, Posteroanterior (PA) chest radiograph obtained 9 days after initial symptom onset shows no definite abnormality. B–E, Follow-up axial chest CT images obtained on the same day as the chest radiograph show multifocal ground-glass opacities (arrows), predominantly located in the peripheral areas of both lungs. After 13 days of conservative management, her respiratory symptoms ameliorated, and a negative RT-PCR test result for SARS-CoV-2 was obtained. RT-PCR was repeated twice to confirm this negative result.

Figure 2.

Mild cough and hemoptysis in a 64-year-old woman who was a caregiver in a hospital where SARS-CoV-2–infected patients were present. She underwent a screening test for SARS-CoV-2, and RT-PCR test results were positive. A, Anteroposterior supine chest radiograph obtained 7 days after symptom onset shows ill-defined consolidation (arrows) in the peripheral areas of the right middle to lower lung zones. B–E, Axial chest CT images obtained on the same day as the chest radiograph show irregular consolidation, with fine reticulation (arrows) in the peripheral subpleural areas of both the middle to lower lung zones, mainly in the right lung. She recovered within 14 days with conservative management and was discharged uneventfully after a negative RT-PCR test result.

Figure 3.

Fever, cough, sputum production, and anorexia for 1 week in a 77-year-old woman with asthma, which was managed daily with a long-acting β-agonist salmeterol and corticosteroid inhaler, who presented to a SARS-CoV-2 screening clinic. The test results confirmed SARS-CoV-2 infection, and the patient was transferred to a containment zone at our hospital. A, Anteroposterior chest radiograph obtained 14 days after symptom onset shows bilateral ill-defined ground-glass opacity and consolidation (arrows). B, C, Anteroposterior chest radiograph, B, obtained 19 days after symptom onset shows an increase in the extent of consolidation (arrows) after the patient’s symptoms worsened. Despite the use of extracorporeal membrane oxygenation (ECMO) in the intensive care unit, diffuse consolidation continued to increase until 4 weeks after the admission period, as depicted on the anteroposterior radiograph in C. D, Axial chest CT image obtained 5 weeks after symptom onset shows diffuse consolidation with air bronchogram and pneumothorax (arrowheads), clinically indicating acute respiratory distress syndrome. The patient died that day owing to sepsis and multiorgan failure.

Figure 4.

Fever and myalgia in a 61-year-old man with a history of chronic pleurisy 48 years earlier who presented to a SARS-CoV-2 screening clinic. He had attended a religious meeting where people with SARS-CoV-2 infection had been identified 14 days earlier. A, Initial PA chest radiograph (obtained 14 days after symptom onset) shows patchy consolidation in the right upper lung zone. B, C, Axial CT images obtained on the same day as the chest radiograph show patchy consolidation with surrounding ground-glass opacity in the central area of the right upper lobe. Note the calcified fibrothorax with chronic left pleural effusion in the left hemithorax. D–F, PA radiograph, D, and axial CT images, E, F, show that the extent of consolidation and ground-glass opacity increased over 3 days. After intensive conservative care, symptoms were relieved, and the extent of consolidation gradually decreased. G–I, Follow-up PA radiograph, G, and axial CT images, H,I, obtained after 7 days (24 days from symptom onset) show residual multifocal ground-glass opacity in both lungs. J–L, PA chest radiograph, J, and axial CT images, K, L, obtained before patient discharge (30 days from symptom onset) show almost complete resolution of ground-glass opacities in both lungs.

Figure 5.

Flow chart shows the role of chest CT to facilitate the diagnosis of SARS-CoV-2 pneumonia. (+) = positive, (−) = negative. *Clinical judgment of the use of chest CT is dependent on the patient risk factors related to COVID-19 and the availability of local medical resources. Patients with mild symptoms of COVID-19 without significant respiratory dysfunction do not require chest CT. Chest CT is considered in patients with moderate to severe symptoms with pulmonary dysfunction or damage.