COVID-19 CT scan

Jump to navigation Jump to search

For COVID-19 frequently asked inpatient questions, click here
For COVID-19 frequently asked outpatient questions, click here

COVID-19 Microchapters



Frequently Asked Outpatient Questions

Frequently Asked Inpatient Questions

Patient Information


Historical Perspective




Differentiating COVID-19 from other Diseases

Epidemiology and Demographics

Risk Factors


Natural History, Complications and Prognosis


Diagnostic Study of Choice

History and Symptoms

Physical Examination

Laboratory Findings



Echocardiography and Ultrasound

CT scan


Other Imaging Findings

Other Diagnostic Studies


Medical Therapy



Primary Prevention


Secondary Prevention

Future or Investigational Therapies

Ongoing Clinical Trials

Case Studies

Case #1

COVID-19 CT scan On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides


American Roentgen Ray Society Images of COVID-19 CT scan

All Images
Echo & Ultrasound
CT Images

Ongoing Trials at Clinical

US National Guidelines Clearinghouse

NICE Guidance

FDA on COVID-19 CT scan

CDC on COVID-19 CT scan

COVID-19 CT scan in the news

Blogs on COVID-19 CT scan

Directions to Hospitals Treating Psoriasis

Risk calculators and risk factors for COVID-19 CT scan

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sabawoon Mirwais, M.B.B.S, M.D.[2] Syed Hassan A. Kazmi BSc, MD [3] Aditya Ganti M.B.B.S. [4] Nasrin Nikravangolsefid, MD-MPH [5]


Non-contrast Chest CT scan is an effective method for the rapid diagnosis of COVID-19 and monitoring the disease progression. Chest CT scan findings in patients infected with coronavirus can include unilateral or bilateral pneumonia, mottling and ground glass opacity, focal or multifocal opacities, consolidation, and septal thickening with subpleural and lower lobe involvement.

CT scan

  • Non-contrast Chest CT scan is an effective method not only for the rapid diagnosis of COVID-19 but also for monitoring the disease progression. [1]
  • Given the high sensitivity of chest CT, it can be used in suspected patients with negative RT-PCR. [2]
  • Various chest CT features have been found diagnostic for COVID-19 that are associated with:
    • Duration of illness
    • Severity of illness
  • Bilateral ground glass opacities ± consolidation in posterior and peripheral lung regions are considered as the hallmark for COVID-19. [3]
  • However, there are a large number of typical and atypical chest CT findings for COVID-19 that are summarized in the figure below. [4] [5]

Key CT Findings in COVID-19

CT manifestations of COVID-19
CT findings Definition CT picture
Ground glass opacity
  • Hazy opacity in the lungs with well defined bronchial and vascular margins
  • the most common imaging finding
  • due to infection, chronic interstitial lung disease, and acute lung injury
  • a parenchymal density with ill-defined bronchial and vascular margins
  • filling with infectious material [fluid, cells, tissue]
  • due to cellular exudates in alveoli
  • The presence of consolidation is a sign of disease progression
Crazy paving pattern
  • Septal thickening of inter and intra-lobar regions
  • with the background of the Ground glass opacity
  • Similar to paving stones
  • Due to alveolar edema and acute inflammation of the lung
  • Sign of progression

Reticuldar pattern
  • Linear opacities in the lungs
  • Due to Interstitial thickening of inter and intralobular septa
Air bronchogram
  • Air-filled bronchi
  • Low attenuated areas in the lung
  • Irreversible dilatation of the lung airways
  • Bronchus diameter more than 1.5 cm
  • due to inflammation, obstruction and impaired clearance
Pleural effusion

Radiological Society of North America

The Radiological Society of North America (RSNA) classified CT findings of COVID-19 infection into four categories which were endorsed by the Society of Thoracic Radiology and the American College of Radiology (ACR):

RSNA CT findings classification of Covid-19[10]
Typical appearance
  • Peripheral, bilateral, GGO +/- consolidation or visible intralobular lines (“crazy paving” pattern)
  • Multifocal GGO of rounded morphology +/- consolidation or visible intralobular lines (“crazy paving” pattern)
  • reverse halo sign or other findings of organizing pneumonia
Indeterminate appearance Absence of typical CT findings and the presence of
  • Multifocal, diffuse, perihilar, or unilateral GGO +/- consolidation lacking a specific distribution and are non-rounded or non-peripheral
  • Few very small GGO with a non-rounded and non-peripheral distribution
Atypical appearance Absence of typical or indeterminate features and the presence of
  • Isolated lobar or segmental consolidation without GGO
  • Discrete small nodules (e.g. centrilobular, tree-in-bud)
  • Lung cavitation
  • Smoother interlobular septal thickening with pleural effusion
Negative for pneumonia No CT features to suggest pneumonia, in particular, absent GGO and consolidation

CT Examples of COVID-19

CT scan showing pulmonary focal opacity in a patient infected with COVID-19. [11]
CT scan showing pulmonary multifocal opacities in a patient infected with COVID-19. [12]

CT shows bilateral, multilobar large areas of ground-glass opacities with septal thickening and a crazy-paving pattern.[13]
CT shows bilateral multilobar peripheral ground-glass opacities in both lungs predominantly in mid to lower zones.[14]


  1. Xu B, Xing Y, Peng J, Zheng Z, Tang W, Sun Y; et al. (2020). "Chest CT for detecting COVID-19: a systematic review and meta-analysis of diagnostic accuracy". Eur Radiol. doi:10.1007/s00330-020-06934-2. PMC 7227176 Check |pmc= value (help). PMID 32415585 Check |pmid= value (help).
  2. Fang Y, Zhang H, Xie J, Lin M, Ying L, Pang P; et al. (2020). "Sensitivity of Chest CT for COVID-19: Comparison to RT-PCR". Radiology: 200432. doi:10.1148/radiol.2020200432. PMC 7233365 Check |pmc= value (help). PMID 32073353 Check |pmid= value (help).
  3. Chung M, Bernheim A, Mei X, Zhang N, Huang M, Zeng X; et al. (2020). "CT Imaging Features of 2019 Novel Coronavirus (2019-nCoV)". Radiology. 295 (1): 202–207. doi:10.1148/radiol.2020200230. PMC 7194022 Check |pmc= value (help). PMID 32017661 Check |pmid= value (help).
  4. 4.0 4.1 4.2 Ye Z, Zhang Y, Wang Y, Huang Z, Song B (2020). "Chest CT manifestations of new coronavirus disease 2019 (COVID-19): a pictorial review". Eur Radiol. doi:10.1007/s00330-020-06801-0. PMC 7088323 Check |pmc= value (help). PMID 32193638 Check |pmid= value (help).
  5. Sun Z, Zhang N, Li Y, Xu X (2020). "A systematic review of chest imaging findings in COVID-19". Quant Imaging Med Surg. 10 (5): 1058–1079. doi:10.21037/qims-20-564. PMC 7242306 Check |pmc= value (help). PMID 32489929 Check |pmid= value (help).
  6. 6.0 6.1 6.2 6.3 6.4 Bernheim A, Mei X, Huang M, Yang Y, Fayad ZA, Zhang N; et al. (2020). "Chest CT Findings in Coronavirus Disease-19 (COVID-19): Relationship to Duration of Infection". Radiology. 295 (3): 200463. doi:10.1148/radiol.2020200463. PMC 7233369 Check |pmc= value (help). PMID 32077789 Check |pmid= value (help).
  7. Xu X, Yu C, Qu J, Zhang L, Jiang S, Huang D; et al. (2020). "Imaging and clinical features of patients with 2019 novel coronavirus SARS-CoV-2". Eur J Nucl Med Mol Imaging. 47 (5): 1275–1280. doi:10.1007/s00259-020-04735-9. PMC 7080117 Check |pmc= value (help). PMID 32107577 Check |pmid= value (help).
  8. Lei, Junqiang; Li, Junfeng; Li, Xun; Qi, Xiaolong (2020). "CT Imaging of the 2019 Novel Coronavirus (2019-nCoV) Pneumonia". Radiology: 200236. doi:10.1148/radiol.2020200236. ISSN 0033-8419.
  9. Pan, Feng; Ye, Tianhe; Sun, Peng; Gui, Shan; Liang, Bo; Li, Lingli; Zheng, Dandan; Wang, Jiazheng; Hesketh, Richard L.; Yang, Lian; Zheng, Chuansheng (2020). "Time Course of Lung Changes at Chest CT during Recovery from Coronavirus Disease 2019 (COVID-19)". Radiology. 295 (3): 715–721. doi:10.1148/radiol.2020200370. ISSN 0033-8419.
  10. Simpson, Scott; Kay, Fernando U.; Abbara, Suhny; Bhalla, Sanjeev; Chung, Jonathan H.; Chung, Michael; Henry, Travis S.; Kanne, Jeffrey P.; Kligerman, Seth; Ko, Jane P.; Litt, Harold (2020). "Radiological Society of North America Expert Consensus Statement on Reporting Chest CT Findings Related to COVID-19. Endorsed by the Society of Thoracic Radiology, the American College of Radiology, and RSNA". Radiology: Cardiothoracic Imaging. 2 (2): e200152. doi:10.1148/ryct.2020200152. ISSN 2638-6135.
  11. Case courtesy of Medico Assistente Dr. Chong Keng Sang, Sam, <a href=""></a>. From the case <a href="">rID: 73890</a>
  12. Case courtesy of Medico Assistente Dr. Chong Keng Sang, Sam, <a href=""></a>. From the case <a href="">rID: 73890</a>
  13. Case courtesy of Dr Antonio Rodrigues de Aguiar Neto, <a href=""></a>. From the case <a href="">rID: 76921</a>
  14. Case courtesy of Dr Bahman Rasuli, <a href=""></a>. From the case <a href="">rID: 75768</a>