Mustansiriya Medical Journal

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 19  |  Issue : 1  |  Page : 1--5

Spectrum of chest computerized tomographic findings in novel coronavirus disease-19


Suhail Rafiq, Musaib Ahmad Dar, Inayat Elahi, Irshad Mohi Ud Din 
 Department of Radiodiagnosis, GMC, Srinagar, Jammu and Kashmir, India

Correspondence Address:
Dr. Musaib Ahmad Dar
Department of Radiodiagnosis, GMC, Srinagar, Jammu and Kashmir
India

Abstract

Background: Coronavirus disease-19 (COVID-19) is a zoonotic viral disease caused by nonsegmented, enveloped, positive-sense, single-strand ribonucleic acid coronavirus. Recent outbreak started in Wuhan, China, where a new type of coronavirus was isolated from respiratory samples such as bronchoalveolar lavage and sputum of patients developing respiratory symptoms. The World Health Organization declared COVID-19 a pandemic on January 20, 2020. On April 6, 1,288,080 were infected with this virus with 70,567 deaths. Computerized tomography (CT) is the investigation of choice for diagnosing, managing, and accessing temporal changes in COVID-19. Objective: The objective of this study is to describe the chest CT findings in documented nCovid-19-positive patients. Methodology: This was a retrospective observational study done in Government Medical College, Chest Disease Hospital from February 20 to April 25, 2020. Forty-eight patients with COVID-19 reverse transcriptase-polymerase chain reaction-positive test were scanned on 64 slice Somatom CT scanner and findings analyzed. All patients with previously underlying chest disease were excluded. Results: The various chest findings in the nCovid-19-positive patients include ground glassing, (81.25%), consolidation (56.25%), nodules (43.75%), halo sign (31.25%), crazy paving pattern (50%), air bronchogram (12.5%), air bubble sign (6.25%), vascular enlargement (25%), reversed halo sign or atoll sign (18.75%), bronchial wall thickening (6.25%), and mosaic attenuation (6.25%). None of the patients had pleural effusion. Conclusion: Characteristic CT findings of COVID-19 can help radiologists in the early diagnosis of symptomatic patients in whom testing is awaited. Bilateral peripheral ground-glass opacities with consolidation in dependent parts of the lung along with the absence of pleural effusion were the most common abnormality.



How to cite this article:
Rafiq S, Dar MA, Elahi I, Din IM. Spectrum of chest computerized tomographic findings in novel coronavirus disease-19.Mustansiriya Med J 2020;19:1-5


How to cite this URL:
Rafiq S, Dar MA, Elahi I, Din IM. Spectrum of chest computerized tomographic findings in novel coronavirus disease-19. Mustansiriya Med J [serial online] 2020 [cited 2020 Nov 25 ];19:1-5
Available from: https://www.mmjonweb.org/text.asp?2020/19/1/1/292710


Full Text



 Introduction



Coronavirus disease-19 (COVID-19) is a zoonotic viral disease caused by nonsegmented, enveloped, positive-sense, single-strand ribonucleic acid coronavirus.[1] Recent outbreak started in Wuhan, China, where a new type of coronavirus was isolated from the respiratory samples such as bronchoalveolar lavage, sputum of patients developing respiratory symptoms. Major symptoms of Covid-19 are fever, cough, breathlessness, and fatigue. The mean incubation period is 5.2 days, with high human-to-human transmission.[2] Before nCovid-19, coronavirus has been associated with middle east respiratory syndrome (MERS), severe acute respiratory syndrome (SARS) coronavirus, and other milder respiratory symptoms. SARS was transmitted through large droplets and direct inoculation.[3] MERS coronavirus is transmitted mainly through nonhuman, zoonotic sources such as bats and camels.[4],[5] The World Health Organization declared COVID-19 a pandemic on January 20, 2020.[6] On April 6, 1,288,080 were infected with this virus with 70,567 deaths.

Computerized tomography (CT) is the investigation of choice for diagnosing, managing, and accessing temporal changes in COVID-19.[7] Virus binds to angiotensin-converting enzyme-2 (ACE2) receptor starting with pulmonary interstitial changes followed by parenchymal changes.[8] Bilateral peripherally distributed ground-glass opacities (GGO) with or without consolidation in posterior aspect of lungs has been characteristic imaging finding on CT.[9],[10]

Objective

The objective of this study is to describe the chest CT findings in documented nCovid-19-positive patients.

 Methodology



This was a retrospective observational study done in Government Medical College, Chest Disease Hospital from February 20 to April 25, 2020. Forty-eight patients with COVID-19 reverse transcriptase-polymerase chain reaction (RT-PCR) positive test was scanned on 64 slice Somatom CT scanner. All patients with previously underlying chest disease were excluded. We describe chest CT Imaging findings in these cases. Chest CT findings vary with time course and severity of disease.[11],[12] Categorical values were presented with absolute and relative frequencies (%).

 Results



Most of our patients were in the age group of more than 60 years with predominance of male patients [Table 1] and [Table 2]. The various findings found in our study patients are summarized in [Table 3].{Table 1}{Table 2}{Table 3}

 Discussion



Ground glassing

Ground glassing is defined as the areas of increased pulmonary attenuation without obscuration of lung markings caused by partial replacement of air in air spaces by fluid, cells, etc.[13] In patients with COVID-19 peripheral, subpleural areas of ground glassing with unilateral or bilateral distribution are most commonly seen.[14],[15],[16] GGO as the most common imaging found in 98% cases.[17] In our study, ground glassing [Figure 1], [Figure 2], [Figure 3], [Figure 4] was found in 39 out of 48 patients (81.25%).{Figure 1}{Figure 2}{Figure 3}{Figure 4}

Consolidation

Consolidation is defined as the areas of increased pulmonary parenchymal attenuation that obscures the margins of underlying vessels and airway walls.[13] Multiple peripheral focal or segmental consolidations in peri-brochovascular distribution with occurrence rate of 2%–64% are seen in Covid patients.[17],[18],[19] In our study, multiple consolidations [Figure 5], [Figure 6], [Figure 7] was found 56.25% of the total number of patients (27 out of 48 patients).{Figure 5}{Figure 6}{Figure 7}

Nodules

A nodule is defined as rounded or irregular opacity with well- or poorly defined margins with size <3 cm in diameter.[13] Multiple solid irregular nodules or nodule with surrounding halo have been found in 3%–13% of COVID-19 patients.[14],[20] In our study, 43.75% of the patients were found to have nodules [Figure 2].

Halo sign

Halo sign is defined as the area of ground glassing surrounding nodule or mass.[13] Li et al.[21] reported a case of halo sign in a 27-year-old female COVID-19 patient. In our study, 15 out of 48 patients had Halo sign [Figure 2] (31.25%).

Crazy-paving pattern

Crazy-paving pattern is defined as areas of inter/intralobular septal thickening with superimposed ground glassing.[13] Crazing paving is seen in 5%–36% COVID-19 patients.[16],[18] In our study, 50% of the patients were found to have crazy paving patterns [Figure 1].

Air bronchogram

Air-filled bronchi seen within opaque (high attenuation) airless lung/Consolidation has been documented in CT of Covid patients.[15],[22] In our study, we found 6 out of 48 patients had air bronchogram sign within consolidations [Figure 5] (12.5%).

Air bubble sign

Air bubble sign refers to a small air-containing space in consolidation or ground glassing. Shi et al. termed this sign as round cystic change in their study,[11] whereas Kong et al. reported it as cavity sign.[23] In our study, only 3 out of 48 patients were found to have air bubble sign [Figure 3].

Vascular enlargement

The presence of dilated pulmonary vessels around and within the lesions on CT images was found in RT-PCR-negative COVID-19 patient who was admitted to a hospital 6 days after the symptom onset.[24] In our study, we found 25% of the total number of patients having vascular enlargement [Figure 4].

Reversed halo sign or atoll sign

Atoll sign is defined as the area of ground glassing surrounded by a more or less complete ring-like consolidation.[13] It has been seen in several COVID-19 cases representing disease progression or lesion absorption.[18],[22],[25],[26] In our study, 9 out of 48 patients were found to have reverse Halo sign [Figure 8] which accounted for 18.75% of the total number of patients.{Figure 8}

Bronchial wall thickening

About 10%–20% COVID-19 patients have inflammatory thickening of bronchial wall.[17],[19] The incidence of bronchial wall thickening is more common in severe/critical patients than ordinary patients.[17] In our study, 6.25% (3 out of 48) of the total number of patients had bronchial wall thickening [Figure 7].

Mosaic attenuation

Although mosaic attenuation has not been previously documented in Covid-19 but 3 of our patient had mosaic attenuation [Figure 9], accounting for 6.25%s of the total number of patients.{Figure 9}

Absence of pleural effusion

None of the patients had pleural effusion.

 Summary and Conclusion



Characteristic CT findings of COVID-19 can help radiologists in the early diagnosis of symptomatic patients in whom testing is awaited. Bilateral peripheral ground-glass opacities with consolidation in dependent parts of lung along with the absence of pleural effusion were the most common abnormality. Majority of the patients had combination of above described findings. Other common CT features include crazy paving, nodules, and halo sign. Less common signs include vascular enlargement, Atoll sign, bronchial wall thickening, air bronchogram, and air bubble sign. However, these findings are nonspecific can be seen in different viral pneumonias. Follow-up CT is not recommended in case of cure from disease.

Teaching point

Findings of Covid-19 are similar to cryptogenic organizing pneumonia, but they occur in acute settings following a viral prodrome of fever, cough, fatigability, etc.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Weiss SR, Leibowitz JL. Coronavirus pathogenesis. Adv Virus Res 2011;81:85-164.
2Li Q, Guan X, Wu P, Wang X, Zhou L, Tong Y, et al. Early transmission dynamics in Wuhan, China, of novel coronavirus-infected pneumonia. N Engl J Med 2020;382:1199-207.
3Chan-Yeung M, Xu RH. SARS: Epidemiology. Respirology 2003;8 Suppl:S9-14.
4Mobaraki K, Ahmadzadeh J. Current epidemiological status of Middle East respiratory syndrome coronavirus in the world from 1.1.2017 to 17.1.2018: A cross-sectional study. BMC Infect Dis 2019;19:351.
5MacIntyre CR. The discrepant epidemiology of Middle East respiratory syndrome coronavirus (MERS-CoV). Environ Syst Decis 2014;34:383-90.
6Mahase E. China coronavirus: WHO declares international emergency as death toll exceeds 200. BMJ 2020;368:m408.
7National Health Commission of the People's Republic of China. The Guidlines for the Diagnosis and Treatment of 2019-nCoV Pneumonia (the 5th edition). Available from: http://www.nhc.gov.cn/yzygj/s7653p/202002/d4b895337e19445f8d728fcaf1e3e13a/files/ab6bec7f93e64e7f998d802991203cd6.pdf. [Last accessed on 2020 Mar 08].
8Xu X, Chen P, Wang J, Feng J, Zhou H, Li X, et al. Evolution of the novel coronavirus from the ongoing Wuhan outbreak and modeling of its spike protein for risk of human transmission. Sci China Life Sci 2020;63:457-60.
9Wang D, Hu B, Hu C, Zhu F, Liu X, Zhang J, et al. Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China. JAMA 2020;323:1061-9.
10Chung M, Bernheim A, Mei X, Zhang N, Huang M, Zeng X, et al. CT imaging features of 2019 novel coronavirus (2019-nCoV). Radiology 2020;295:202-7.
11Shi H, Han X, Jiang N, Cao Y, Alwalid O, Gu J, et al. Radiological findings from 81 patients with COVID-19 pneumonia in Wuhan, China: A descriptive study. Lancet Infect Dis 2020;20:425-34
12Pan F, Ye T, Sun P, Gui S, Liang B, Li L, et al. Time course of lung changes on chest CT during recovery from 2019 novel coronavirus (COVID-19) pneumonia. Radiology Feb 2020;295:3.
13Hansell DM, Bankier AA, MacMahon H, McLoud TC, Muller NL, Remy J. Fleischner Society: Glossary of terms for thoracic imaging. Radiology 2008;246:697-722.
14Pan Y, Guan H, Zhou S, Wang Y, Li Q, Zhu T, et al. Initial CT findings and temporal changes in patients with the novel coronavirus pneumonia (2019-nCoV): A study of 63 patients in Wuhan, China. Eur Radiol 2020;30:3306-9.
15Song F, Shi N, Shan F, Zhang Z, Shen J, Lu H, et al. Emerging coronavirus 2019- nCoV pneumonia. Radiology 2020;295:210-7.
16Ng MY, Lee EY, Yang J, Yang F, Li X, Wang H, et al. Imaging profile of the COVID-19 infection: Radiologic findings and literature review. Radiology: Cardiothoracic Imaging 2020;2(1).
17Li JW, Wu F, Guo D, Chen L, Zheng F, Li C. The clinical and chest CT features associated with severe and critical COVID-19 pneumonia. Invest Radiol 2020;55:327-31.
18Bernheim A, Mei X, Huang M, Yang Y, Fayad ZA, Zhang N, et al. Chest CT findings in coronavirus disease-19 (COVID-19): Relationship to duration of infection. Radiology 2020;295(3).
19Wu J, Wu X, Zeng W, Guo D, Fang Z, Chen L, et al. Chest CT findings in patients with corona virus disease 2019 and its relationship with clinical features. Invest Radiol 2020;55:257-61.
20Ai T, Yang Z, Hou H, Zhan C, Chen C, Lv W, et al. Correlation of chest CT and RTPCR testing in coronavirus disease 2019 (COVID-19) in China: A report of 1014 cases. Radiology Feb 2020;
21Li X, Zeng X, Liu B, Yu Y. COVID-19 infection presenting with CT halo sign. Radiology: Cardiothoracic Imaging 2020;2:1.
22Yoon S, Lee K, Kim J, Lee YK, Ko H, Kim KH, et al. Chest radiographic and CT findings of the 2019 novel coronavirus disease (COVID-19): Analysis of nine patients treated in Korea. Korean J Radiol 2020;21:494-500.
23Kong W, Agarwal PP. Chest Imaging Appearance of COVID-19 Infection. Radiology: Cardiothoracic Imaging 2020;2(1).
24Xie X, Zhong Z, ZhaoW, Zheng C, Wang F, Liu J. Chest CT for typical 2019-nCoV pneumonia: Relationship to negative RTPCR testing. Radiology 2020.
25Huang P, Liu T, Huang L, Liu H, Lei M, Xu W, et al. Use of chest CT in combination with negative RT-PCR assay for the 2019 novel coronavirus but high clinical suspicion. Radiology 2020;295:22-3.
26Xu R, Du M, Li L, Zhen Z, Wang H, Hu X. CT imaging of one extended family cluster of corona virus disease 2019 (COVID-19) including adolescent patients and “silent infection”. Quant Imaging Med Surg 2020;10:800-4.