Comprehensive literature review on the radiographic findings, imaging modalities, and the role of radiology in the COVID-19 pandemic

Figure 1  Model of infected lung through pathological and radiological perspectives.

Figure 2 A collection of chest radiographs that displays some of the common and rare findings of coronavirus disease 2019 pneumonia[15,19-22]. A: Bilateral patchiness; B: Unilateral ground glass opacification; C: Subcutaneous emphysema secondary to a pneumothorax; D: Linear and patchy interstitial infiltrate in the right basal zone; E: Nodular appearance of the right lobe parenchyma; F: reticular appearance of the consolidation bilaterally. A: Citation: Singh B, Kaur P, Reid RJ, Shamoon F, Bikkina M. COVID-19 and Influenza Co-Infection: Report of Three Cases. Cureus 2020; 12: e9852. Copyright ©The Author(s) 2020. Published by Cureus; B: Citation: Martini K, Blüthgen C, Walter JE, Messerli M, Nguyen-Kim TD, Frauenfelder T. Accuracy of Conventional and Machine Learning Enhanced Chest Radiography for the Assessment of COVID-19 Pneumonia: Intra-Individual Comparison with CT. Journal of Clinical Medicine 2020;.9: 3576 Copyright ©The Author(s) 2020. Published by MDPI, Basel, Switzerland; C: Citation: Rampa L, Miceli A, Casilli F, Biraghi T, Barbara B, Donatelli F. Lung complication in COVID-19 convalescence: A spontaneous pneumothorax and pneumatocele case report. Journal of Respiratory Diseases and Medicine 2020; 2. Copyright ©The Author(s) 2020. Published by Open-access article; D: Citation: Kaufman A, Naidu S, Ramachandran S, Kaufman D, Fayad Z, Mani V. Review of radiographic findings in COVID-19. World Journal of Radiology 2020; 12: 142-55. Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc; E and F: Citation: Yasin R, Gouda W. Chest X-ray findings monitoring COVID-19 disease course and severity. The Egyptian Journal of Radiology and Nuclear Medicine 2020; 51: 193. Copyright ©The Author(s) 2020. Published by BMJ.

Figure 3 Summary of the frequency distribution of classical and ancillary computed tomography imaging findings in coronavirus disease 2019 pneumonia. The whiskers indicate the 95% confidence interval. GGO: Ground-glass opacity.

Figure 4 A collection of chest computed tomography that displays some of the classical findings of coronavirus disease 2019 pneumonia[26-28]. A: Ground-glass opacity (GGO); B: Consolidation and air bronchogram; C: Crazy paving; D: GGO superimposed with consolidation; E: Bronchiectasis, reticular thickening, with vascular enlargement; F: Pleural adhesion. A, B, E and F: Citation: Fu Z, Tang N, Chen Y, Ma L, Wei Y, Lu Y, Ye K, Liu H, Tang F, Huang G, Yang Y, Xu F. CT features of COVID-19 patients with two consecutive negative RT-PCR tests after treatment. Science Report 2020; 10: 11548. Copyright ©The Author(s) 2020. Published by Springer Nature; C: Citation: Gillespie M, Flannery P, Schumann JA, Dincher N, Mills R, Can A. Crazy-Paving: A Computed Tomographic Finding of Coronavirus Disease 2019. Clinical Practice and Cases in Emergency Medicine 2020; 4: 461-463. Copyright ©The Author(s) 2020. Published by UC Irvine; D: Citation: Ali TF, Tawab MA, ElHariri MA. CT chest of COVID-19 patients: what should a radiologist know? Egyptian Journal of Radiology and Nuclear Medicine 2020; 51: 120. Copyright ©The Author(s) 2020. Published by Springer Nature.

Figure 5 Summary of the frequency distribution of lesions in the lung lobes on computed tomography imaging of coronavirus disease 2019 patients. CI: Confidence interval; LLL: Left lower lobe; LUL: Left upper lobe (LUL); RLL: Right lower lobe; RML: Right middle lobe; RUL: Right upper lobe.

Figure 6 Summary of the frequency distribution of classical and ancillary computed tomography imaging findings in coronavirus disease 2019 pneumonia. The whiskers indicate the 95% confidence interval. The data are adapted from the meta-analysis conducted by Ojha et al[31].

Figure 7 A collection of chest computed tomography that displays some of the atypical findings of coronavirus disease 2019 pneumonia[32-36]. A: Comb sign in the right lobe characterized by vascular enlargement; B: Curvilinear opacities in the subpleural area; C: Reticular pattern bilaterally; D: Multiple nodules and cavitation; E: Bilateral hilar lymphadenopathy; F: Atoll sign also known as reverse halo. A: Citation: Kwee TC, Kwee RM. Chest CT in COVID-19: What the radiologist needs to know. Radiographics 2020; 40: 1848-1865. Copyright ©The Author(s) 2021. Published by Radiographics; B and F: Citation: Kong W, Agarwal PP. Chest imaging appearance of COVID-19 infection. Radiology: Cardiothoracic Imaging 2020; 2: e200028. Copyright ©The Author(s) 2020. Published by the Radiological Society of North America, Inc; C: Citation: Meirelles GSP. COVID-19: A brief update for radiologists. Radiologia Brasileira 2020; 53: 320-328. Copyright ©The Author(s) 2020. Published by Radiology brasil; D: Citation: Zhang Q, Douglas A, Abideen ZU, Khanal S, Tzarnas S. Novel coronavirus (2019-nCoV) in disguise. Cureus 2020; 12: e7521. Copyright ©The Author(s) 2020. Published by Cureus; E: Citation: Mughal MS, Rehman R, Osman R, Kan N, Mirza H, Eng MH. Hilar lymphadenopathy, a novel finding in the setting of coronavirus disease (COVID-19): A case report. Journal of Medical Case Reports 2020; 14: 124. Copyright ©The Author(s) 2020. Published by BMC.

Figure 8 Summarizes the frequencies of chest classical and ancillary computed tomography findings at different stages of disease progression (early [n = 155], intermediate [n = 155], and late [n = 155]). Data acquired from Gu et al[41].

Figure 9 Shows a simplified flowchart guiding the triage in patients presenting with respiratory symptoms during the coronavirus disease 2019 pandemic using lung ultrasonography in the emergency department. ¹Unilateral appearance of more than 1 of any 4 criteria means coronavirus disease 2019 suspected. COVID-19: Coronavirus disease 2019; LUS: Lung ultrasonography.

Figure 10  Schematic diagram describing the 12-zone assessed using the lung ultrasonography 12-zone scoring method. The criteria for each score value (0-3) is described and tabulated.

Figure 11  Lung ultrasonography presentation of B-lines (green panel), subpleural consolidations (white panel), and lung ultrasound scores (orange panel) at different lung zones (anterior, lateral, posterior) in patients with a primary diagnosis of coronavirus disease 2019 (n = 11) and without coronavirus disease 2019 (other, n = 38). Boxplots around median and interquartile range (IQR), with outliers within 1.5 IQR of the nearest quartile. Other (extrapulmonary infection/inflammation (n = 10), pneumonia of other etiology (n = 8), exacerbated asthma/ chronic obstructive pulmonary disease (n = 7), pulmonary neoplasia (n = 4), pulmonary embolism (n = 2), congestive heart failure (n = 2), and not documented (n = 5)). Statistically significant outcomes with P < 0.05. Data utilized from Speidel et al[67]. COVID-19: Coronavirus disease 2019; LUSS: Lung ultrasound score.

Figure 12  Basic workflow of the artificial intelligence system. AI: Artificial intelligence; COVID-19: Coronavirus disease 2019.