CASE 17019 Published on 28.10.2020

Progression of COVID-19 pneumonia in chest CT scan


Chest imaging

Case Type

Clinical Cases


Sergio Chacón, Álvaro Antezana, Alfredo Buzzi

Departmen of Radiology-Diagnóstico Medico S.A, Trinidad de Ramos Mejía Hospital, Ramos Mejía, Buenos Aires, Argentina.


62 years, male

Area of Interest Thorax ; Imaging Technique CT
Clinical History

A 62-year-old male patient who arrived at the emergency department presenting fever of 3 days (38.5ºC) and dry cough, no other symptoms associated. Co-morbidities: hypertension treated with valsartan. Negative PCR for influenza A and B.

Imaging Findings

Non-contrast chest CT was obtained with the patient in supine position at the end of inspiration. The CT study was performed in a multidetector GE CT scanner, 128 slices, using international high-resolution protocols.
Figures 1 and 2 show the dynamic changes on chest CT in a patient with COVID-19 infection confirmed by PCR, at three and five days after the onset of symptoms. Figures 1A and 2A show subtle peripheral ground-glass opacities in the lower lobes. Figures 2A and 2B (at the same level as Figures 1A and 1B) show the progression of the lesions that have increased in size and density. Some of them have a rounded shape and interlobular septal thickening; note new ground-glass opacities in Figure 1B.


Background: COVID-19 was described in December 2019 in Wuhan, China, as a cause of pneumonia [1], is caused by SARS-COV-2 virus. Since then, this virus has spread around the world causing several cases of low respiratory tract infection with variable severity affecting most commonly patients between 30-79 years old [2].

Clinical Perspective: The main symptoms include fever, myalgia, dry cough, dyspnoea and loss of senses of taste and smell; uncommon symptoms may include headache, sputum production, diarrhoea and haemoptysis [2]. Pneumonia is present in most of cases of infection for SARS-COV-2 ant that is why imaging play an important role in the assessment and prognosis of the disease. Studies indicate that chest CT has a sensitivity of 97% in patients with positive RT-PCR and 75% with negative RT-PCR. This suggests that chest CT is a sensitivity modality to detect COVID-19 infection2.

Imaging Perspective: the main findings in the COVID-19 pneumonia are ground-glass opacities (GGO) with round morphology with peripheral and posterior distribution, commonly bilateral and affecting two or more lobes, and GGO with consolidation or with interlobular septal thickening. Other findings include reticulation pattern, pleural effusion, pericardial effusion and lymphadenopathy3. Chest CT has a high sensitivity for the diagnosis of COVID-19 pneumonia, but always the diagnosis needs to be confirmed by PCR [2,3].

Outcome: imaging has an important role in the diagnosis, treatment and prognosis of the infection course, it allows the physicians to evaluate the most adequate therapy and the response to it and, finally, it is important to exclude other causes of pulmonary disease that manifest at CT scans with other patterns such as “tree in bud”, which is not commonly seen in COVID-19 infections, and exclude complications. Its role in therapeutic procedures is not well defined because of the lack of complications (in most of the cases seen at this time) such as pleural o pericardial effusions.

Take-Home Message / Teaching Points: The principal imaging findings in COVID-19 pneumonia include focal or multifocal ground-glass opacities, crazy paving pattern or consolidations with peripheral distribution. The presence of pleural effusion, “tree in bud” appearance or adenopathy is less consistent with COVID-19 infection

Differential Diagnosis List
COVID-19 infection confirmed by PCR, pulmonary involvement by chest CT.
Influenza pneumonia
COVID-19 pneumonia
Organising pneumonia
Drug toxicity
Connective tissue disease
Final Diagnosis
COVID-19 infection confirmed by PCR, pulmonary involvement by chest CT.
Case information
DOI: 10.35100/eurorad/case.17019
ISSN: 1563-4086