1 Introduction
Since December 2019, a newly discovered infectious disease named COVID-19 caused by a novel coronavirus (SARS-CoV-2) has wildly spread worldwide. More than six million COVID-19 patients have been confirmed, and thousands of children are also involved in this pandemic all over the world 1-3.
To date, viral nucleic acid testing and chest CT have been considered as the main diagnostic methods for patients with suspected COVID-19 pneumonia. However, in adults, the positive rate of pharyngeal swabs reverse transcription polymerase chain reaction (RT-PCR) is only 59% to 61·3%4,5. For adults, despite the possibility of false positives, the positive rate of chest CT is significantly higher than that of RT-PCR and is considered a more accurate early diagnostic tool 6-9.
For pediatric patients with suspected COVID-19, studies on chest CT values are limited10,11. Some studies have suggested that normal CT or lack of typical features were not uncommon in pediatric patients, especially during the early stage of the diseases 12-15. The most common CT feature of pediatric patients was bilateral ground-glass opacities with a ratio of only 32·7%12. However, the use of CT should be carefully assessed since pediatric patients are sensitive to radiation, and reducing CT scans for children is a top priority.
Compared with adults, the risk of severe or fatal COVID-19 disease is rare while the majority of them were mild cases requiring only conventional therapy for viral pneumonia 12-14. In addition, viral infections, such as influenza virus, coxsackie virus, rubella virus and EB virus, in pediatric patients are very common, so pediatricians often do not initially suspect a diagnosis of COVID-19. However, during this pandemic, this will lead to missed diagnosis of COVID-19 and increase the likelihood of further transmission of the disease from undiagnosed children to healthy individuals.
In this pandemic emergency, it is important to optimize limited medical resources, reduce the radiation dose for children and obtain a rapid and accurate diagnosis. Thus, we performed a longitudinal study to analyze the clinical characteristics, CT manifestations, and RT-PCR changes to explore early diagnosis strategies for pediatric patients.