Chest CT images
Chest CT scan could offer reliable evidence for the detection of
SARS-CoV-2 infection. Japanese scholar Inui et.al
conduct a study
on the chest CT of 112 cases from the cruise ship “Diamond Princess”
with COVID-19[34]. They found 73% (82/112) were asymptomatic
infections, 54% (44/82) of the asymptomatic cases had lung opacities on
CT. They concluded that asymptomatic cases showed more GGO(ground-glass
opacity)than consolidation and milder extension of lung parenchymal
opacities. Another study is from the Central Hospital of Wuhan, China.
Wang et al. make a retrospective analysis on the CT images from 159
asymptomatic cases with COVID-19 and found that
the
lesions in the lung were mostly peripheral distribution in 142 cases
(89.3%) and bilateral distribution in 91 cases (57.2%), as well as
more than two lung lobes were involved in 100 cases (62.9%). Most of
the lesions were GGO (95%). In short-term follow-up, the majority of
asymptomatic patients had a good prognosis (73.7 %) and none of them
had extrapulmonary complications[35]. Hu et al. present the
characteristics of chest CT images of 24 asymptomatic cases (but 5 cases
developed symptoms later) and found
that 8/19 cases showed ground-glass or patchy shadows, 4/19 cases showed
stripe
shadows which seems as an atypical image finding, and the rest 7/19
cases showed normal images[25].
These studies found that
the
chest CT images of asymptomatic cases were mainly GGO and most of them
restored quickly, even though the sample size was small. However, the
first two surveys did not indicate whether any of these asymptomatic
cases developed symptoms later and what was the prognosis with different
chest CT lesions. We expect more data on chest CT findings of the
full-course asymptomatic carriers.