Coronavirus disease 2019 (COVID-19), a highly infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was firstly reported in Wuhan, Hubei Province, China, and rapidly spreads to other domestic cities and countries beyond China [1]. On January 30, 2020, the World Health Organization (WHO) declared this ongoing outbreak as a global public health emergency and raised the risk of COVID-19 to very high at the global level on February 28, 2020 [2]. A total of 88,948 COVID-19 cases with 3043 deaths were confirmed as of March 2, 2020, of which 80,174 were from China and 8774 were from other 64 countries [3]. In COVID-19 diagnosis, real-time reverse transcription polymerase chain reaction (RT-PCR) of viral nucleic acid is regarded as the reference standard; however, recent studies addressed the importance of chest computed tomography (CT) examination in COVID-19 patients with false negative RT-PCR results [4, 5], and reported the CT sensitivity as 98% [6]. Additionally, according to the official diagnosis and treatment protocol (6th edition) declared by the National Health Commission of China [7], CT examination is of great significance not only in diagnosing COVID-19 but also in monitoring disease progression and evaluating therapeutic efficacy.