Can Chest CT Features Distinguish Patients With Negative From Those With Positive Initial RT-PCR Results for Coronavirus Disease (COVID-19)?

AJR Am J Roentgenol. 2021 Jan;216(1):66-70. doi: 10.2214/AJR.20.23012. Epub 2020 May 5.


OBJECTIVE. The purpose of this study was to explore the value of CT in the diagnosis of coronavirus disease (COVID-19) pneumonia, especially for patients who have negative initial results of reverse transcription-polymerase chain reaction (RT-PCR) testing. MATERIALS AND METHODS. Patients with COVID-19 pneumonia from January 19, 2020, to February 20, 2020, were included. All patients underwent chest CT and swab RT-PCR tests within 3 days. Patients were divided into groups with negative (seven patients) and positive (14 patients) initial RT-PCR results. The imaging findings in both groups were recorded and compared. RESULTS. Twenty-one patients with symptoms (nine men, 12 women; age range, 26-90 years) were evaluated. Most of the COVID-19 lesions were located in multiple lobes (67%) in both lungs (72%) in our study. The main CT features were ground-glass opacity (95%) and consolidation (72%) with a subpleural distribution (100%). Otherwise, 33% of patients had other lesions around the bronchovascular bundle. The other CT features included air bronchogram (57%), vascular enlargement (67%), interlobular septal thickening (62%), and pleural effusions (19%). Compared with that in the group with positive initial RT-PCR results, CT of the group with negative initial RT-PCR results was less likely to show pulmonary consolidation (p < 0.05). CONCLUSION. The less pulmonary consolidation found at CT, the greater is the possibility of negative initial RT-PCR results. Chest CT is important in the screening of patients in whom disease is clinically suspected, especially those who have negative initial RT-PCR results.

Keywords: COVID-19; CT; RT-PCR; coronavirus disease; pneumonia; reverse transcription–polymerase chain reaction.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • COVID-19 / diagnostic imaging*
  • COVID-19 Testing
  • Diagnosis, Differential
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pneumonia, Viral / diagnostic imaging*
  • Pneumonia, Viral / virology
  • Radiography, Thoracic
  • Reverse Transcriptase Polymerase Chain Reaction
  • SARS-CoV-2
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / methods*