Retrospective Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Feb 6, 2023; 11(4): 756-763
Published online Feb 6, 2023. doi: 10.12998/wjcc.v11.i4.756
Chest computed tomography findings of the Omicron variants of SARS-CoV-2 with different cycle threshold values
Wei-Feng Ying, Qiong Chen, Zhi-Kui Jiang, Da-Guang Hao, Ying Zhang, Qian Han
Wei-Feng Ying, Qiong Chen, Da-Guang Hao, Ying Zhang, Department of Radiology, Shanghai Xuhui Dahua Hospital, Shanghai 200237, China
Zhi-Kui Jiang, Qian Han, Department of Clinical Laboratory, Shanghai Xuhui Dahua Hospital, Shanghai 200237, China
Author contributions: Chen Q designed the research study; Jiang ZK and Han Q performed the research; Hao DG and Zhang Y contributed new reagents and analytic tools; Ying WF analyzed the data and wrote the manuscript; All authors have read and approved the final manuscript.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of Shanghai Xuhui Dahua Hospital (Approval No. 20220804).
Informed consent statement: All study participants or their legal guardian provided informed written consent about personal and medical data collection prior to study enrolment.
Conflict-of-interest statement: The authors state that there are no conflicts of interest to report.
Data sharing statement: Technical appendix, statistical code, and dataset available from the corresponding author at cq1444@sina.com upon reasonable request.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Qiong Chen, MSc, Chief Doctor, Department of Radiology, Shanghai Xuhui Dahua Hospital, No. 901 Lao’humin Road, Xuhui District, Shanghai 200237, China. cq1444@sina.com
Received: September 1, 2022
Peer-review started: September 1, 2022
First decision: November 22, 2022
Revised: November 29, 2022
Accepted: January 12, 2023
Article in press: January 12, 2023
Published online: February 6, 2023
Processing time: 157 Days and 21.2 Hours
Abstract
BACKGROUND

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mainly infects the upper respiratory tract. This study aimed to determine whether the probability of pulmonary infection and the cycle threshold (Ct) measured using the fluorescent polymerase chain reaction (PCR) method were related to pulmonary infections diagnosed via computed tomography (CT).

AIM

To analyze the chest CT signs of SARS-CoV-2 Omicron variant infections with different Ct values, as determined via PCR.

METHODS

The chest CT images and PCR Ct values of 331 patients with SARS-CoV-2 Omicron variant infections were retrospectively collected and categorized into low (< 25), medium (25.00-34.99), and high (≥ 35) Ct groups. The characteristics of chest CT images in each group were statistically analyzed.

RESULTS

The PCR Ct values ranged from 13.36 to 39.81, with 99 patients in the low, 155 in the medium, and 77 in the high Ct groups. Six abnormal chest CT signs were detected, namely, focal infection, patchy consolidation shadows, patchy ground-glass shadows, mixed consolidation ground-glass shadows, subpleural interstitial changes, and pleural changes. Focal infections were less frequent in the low Ct group than in the medium and high Ct groups; these infections were the most common sign in the medium and high Ct groups. Patchy consolidation shadows and pleural changes were more frequent in the low Ct group than in the other two groups. The number of patients with two or more signs was greater in the low Ct group than in the medium and high Ct groups.

CONCLUSION

The chest CT signs of patients with pulmonary infection caused by the Omicron variants of SARS-CoV-2 varied depending on the Ct values. Identification of the characteristics of Omicron variant infection can help subsequent planning of clinical treatment.

Keywords: COVID-19; SARS-CoV-2; Omicron variant; Computed tomography; Cycle threshold; Polymerase chain reaction

Core Tip: Pulmonary infections caused by the Omicron variant of severe acute respiratory syndrome coronavirus 2 were highly correlated with cycle threshold (Ct) values. Lower Ct values were associated with a higher incidence and degree of pulmonary damage.