Thoracic imaging tests for the diagnosis of COVID-19

Research output: Contribution to journalReview articlepeer-review

Authors

  • Cochrane COVID-19 Diagnostic Test Accuracy Group

Colleges, School and Institutes

External organisations

  • University of Ottawa
  • Amsterdam University Medical Centers
  • Utrecht University
  • McMaster University
  • Radiology Department
  • University Hospital Birmingham
  • Centre for Academic Primary Care.
  • University Medical Center Utrecht
  • Université de Paris

Abstract

BACKGROUND: The respiratory illness caused by SARS-CoV-2 infection continues to present diagnostic challenges. Our 2020 edition of this review showed thoracic (chest) imaging to be sensitive and moderately specific in the diagnosis of coronavirus disease 2019 (COVID-19). In this update, we include new relevant studies, and have removed studies with case-control designs, and those not intended to be diagnostic test accuracy studies.

OBJECTIVES: To evaluate the diagnostic accuracy of thoracic imaging (computed tomography (CT), X-ray and ultrasound) in people with suspected COVID-19.

SEARCH METHODS: We searched the COVID-19 Living Evidence Database from the University of Bern, the Cochrane COVID-19 Study Register, The Stephen B. Thacker CDC Library, and repositories of COVID-19 publications through to 30 September 2020. We did not apply any language restrictions.

SELECTION CRITERIA: We included studies of all designs, except for case-control, that recruited participants of any age group suspected to have COVID-19 and that reported estimates of test accuracy or provided data from which we could compute estimates.

DATA COLLECTION AND ANALYSIS: The review authors independently and in duplicate screened articles, extracted data and assessed risk of bias and applicability concerns using the QUADAS-2 domain-list. We presented the results of estimated sensitivity and specificity using paired forest plots, and we summarised pooled estimates in tables. We used a bivariate meta-analysis model where appropriate. We presented the uncertainty of accuracy estimates using 95% confidence intervals (CIs).

MAIN RESULTS: We included 51 studies with 19,775 participants suspected of having COVID-19, of whom 10,155 (51%) had a final diagnosis of COVID-19. Forty-seven studies evaluated one imaging modality each, and four studies evaluated two imaging modalities each. All studies used RT-PCR as the reference standard for the diagnosis of COVID-19, with 47 studies using only RT-PCR and four studies using a combination of RT-PCR and other criteria (such as clinical signs, imaging tests, positive contacts, and follow-up phone calls) as the reference standard. Studies were conducted in Europe (33), Asia (13), North America (3) and South America (2); including only adults (26), all ages (21), children only (1), adults over 70 years (1), and unclear (2); in inpatients (2), outpatients (32), and setting unclear (17). Risk of bias was high or unclear in thirty-two (63%) studies with respect to participant selection, 40 (78%) studies with respect to reference standard, 30 (59%) studies with respect to index test, and 24 (47%) studies with respect to participant flow. For chest CT (41 studies, 16,133 participants, 8110 (50%) cases), the sensitivity ranged from 56.3% to 100%, and specificity ranged from 25.4% to 97.4%. The pooled sensitivity of chest CT was 87.9% (95% CI 84.6 to 90.6) and the pooled specificity was 80.0% (95% CI 74.9 to 84.3). There was no statistical evidence indicating that reference standard conduct and definition for index test positivity were sources of heterogeneity for CT studies. Nine chest CT studies (2807 participants, 1139 (41%) cases) used the COVID-19 Reporting and Data System (CO-RADS) scoring system, which has five thresholds to define index test positivity. At a CO-RADS threshold of 5 (7 studies), the sensitivity ranged from 41.5% to 77.9% and the pooled sensitivity was 67.0% (95% CI 56.4 to 76.2); the specificity ranged from 83.5% to 96.2%; and the pooled specificity was 91.3% (95% CI 87.6 to 94.0). At a CO-RADS threshold of 4 (7 studies), the sensitivity ranged from 56.3% to 92.9% and the pooled sensitivity was 83.5% (95% CI 74.4 to 89.7); the specificity ranged from 77.2% to 90.4% and the pooled specificity was 83.6% (95% CI 80.5 to 86.4). For chest X-ray (9 studies, 3694 participants, 2111 (57%) cases) the sensitivity ranged from 51.9% to 94.4% and specificity ranged from 40.4% to 88.9%. The pooled sensitivity of chest X-ray was 80.6% (95% CI 69.1 to 88.6) and the pooled specificity was 71.5% (95% CI 59.8 to 80.8). For ultrasound of the lungs (5 studies, 446 participants, 211 (47%) cases) the sensitivity ranged from 68.2% to 96.8% and specificity ranged from 21.3% to 78.9%. The pooled sensitivity of ultrasound was 86.4% (95% CI 72.7 to 93.9) and the pooled specificity was 54.6% (95% CI 35.3 to 72.6). Based on an indirect comparison using all included studies, chest CT had a higher specificity than ultrasound. For indirect comparisons of chest CT and chest X-ray, or chest X-ray and ultrasound, the data did not show differences in specificity or sensitivity.

AUTHORS' CONCLUSIONS: Our findings indicate that chest CT is sensitive and moderately specific for the diagnosis of COVID-19. Chest X-ray is moderately sensitive and moderately specific for the diagnosis of COVID-19. Ultrasound is sensitive but not specific for the diagnosis of COVID-19. Thus, chest CT and ultrasound may have more utility for excluding COVID-19 than for differentiating SARS-CoV-2 infection from other causes of respiratory illness. Future diagnostic accuracy studies should pre-define positive imaging findings, include direct comparisons of the various modalities of interest in the same participant population, and implement improved reporting practices.

Bibliographic note

Funding Information: Members of the Cochrane COVID-19 Diagnostic Test Accuracy Review Group include the following. The project team (Deeks JJ, Dinnes J, Takwoingi Y, Davenport C, Leeflang MMG, Spijker R, Hooft L, Van den Bruel A, McInnes MDF, Emperador D, Dittrich S); The systematic review teams for each review The project team (Deeks JJ, Dinnes J, Takwoingi Y, Davenport C, Leeflang MMG, Spijker R, Hooft L, Van den Bruel A, McInnes MDF, Emperador D, Dittrich S); The systematic review teams for each review Molecular, antigen, and antibody tests (Adriano A, Beese S, Dretzke J, Ferrante di Ruffano L, Harris I, Price M, Taylor-Phillips S) Signs and symptoms (Stuyf T, Domen J, Horn S) Routine laboratory markers (Yang B, Langendam M, Ochodo E, Guleid F, Holtman G, Verbakel J, Wang J, Stegeman I) Imaging tests (Islam N, Ebrahimzadeh S, Salameh JP, Kazi S, Fabiano N, Treanor L, Absi M, Hallgrimson Z, Van Der Pol CB, Prager R, Hare SS, Dennie C, Jenniskens K, Korevaar DA, Cohen JF, van de Wijgert J, Damen JAAG, Wang J) Molecular, antigen, and antibody tests (Adriano A, Beese S, Dretzke J, Ferrante di Ruffano L, Harris I, Price M, Taylor-Phillips S) Signs and symptoms (Stuyf T, Domen J, Horn S) Routine laboratory markers (Yang B, Langendam M, Ochodo E, Guleid F, Holtman G, Verbakel J, Wang J, Stegeman I) Imaging tests (Islam N, Ebrahimzadeh S, Salameh JP, Kazi S, Fabiano N, Treanor L, Absi M, Hallgrimson Z, Van Der Pol CB, Prager R, Hare SS, Dennie C, Jenniskens K, Korevaar DA, Cohen JF, van de Wijgert J, Damen JAAG, Wang J) The wider team of systematic reviewers from University of Birmingham, UK who assisted with title and abstract screening across the entire suite of reviews for the diagnosis of COVID-19 (Agarwal R, Baldwin S, Berhane S, Herd C, Kristunas C, Quinn L, Scholefield B). The wider team of systematic reviewers from University of Birmingham, UK who assisted with title and abstract screening across the entire suite of reviews for the diagnosis of COVID-19 (Agarwal R, Baldwin S, Berhane S, Herd C, Kristunas C, Quinn L, Scholefield B). We thank Dr Jane Cunningham (World Health Organization) for participation in technical discussions and comments on the manuscript. The Cochrane Central Editorial Service collaborated with Cochrane Infectious Diseases Group (CIDG) on the management of the editorial process. We thank Helen Wakeford and Anne-Marie Stephani (Managing Editors, Central Editorial Service, Cochrane) and Deirdre Walshe (CIDG) for editorial feedback; Gianni Virgili (Contact Editor), Sophie Beese and Bella Harris (Managing Editors) and Marta Roqu? (statistical peer reviewer) from the Cochrane Diagnostic Test Accuracy Reviews Editorial Team; Robin Featherstone (Central Editorial Service, Cochrane) for search peer review; peer reviewers Paul Garner and Robert Walton; consumer referee Shirley Hall; and Denise Mitchell (Central Editorial Service, Cochrane), who copy-edited the review. The CIDG editorial base is funded by UK aid from the UK government for the benefit of low- and middle-income countries (project number 300342-104). The views expressed do not necessarily reflect the UK government?s official policies. Jonathan Deeks is a UK National Institute for Health Research (NIHR) Senior Investigator Emeritus. Yemisi Takwoingi is supported by a NIHR Postdoctoral Fellowship. Jonathan Deeks, Jacqueline Dinnes, and Yemisi Takwoingi are supported by the NIHR Birmingham Biomedical Research Centre. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health and Social Care. Funding Information: Project number: 300342-104 National Institute for Health Research (NIHR), UK Government of Ontario Ministry of Health COVID-19 Rapid Response Research Grant program, Canada Publisher Copyright: Copyright © 2021 The Authors. Cochrane Database of Systematic Reviews published by John Wiley & Sons, Ltd. on behalf of The Cochrane Collaboration.

Details

Original languageEnglish
Article numberCD013639
Number of pages147
JournalCochrane Database of Systematic Reviews
Volume2021
Issue number3
Publication statusPublished - 16 Mar 2021

Keywords

  • Adolescent, Adult, Aged, Bias, COVID-19/diagnostic imaging, COVID-19 Nucleic Acid Testing/standards, Child, Confidence Intervals, Humans, Lung/diagnostic imaging, Middle Aged, Radiography, Thoracic/standards, Reference Standards, Sensitivity and Specificity, Tomography, X-Ray Computed/standards, Ultrasonography/standards, Young Adult

ASJC Scopus subject areas