Purpose: To evaluate the chest CT findings in an environmentally homogeneous cohort from the cruise ship Diamond Princess with coronavirus disease 2019 (COVID-19).
Materials and methods: This retrospective study comprised 104 cases (mean age, 62 years ± 16 [standard deviation], range, 25-93 years) with COVID-19 confirmed with reverse-transcription polymerase change reaction findings. CT images were reviewed, and the CT severity score was calculated for each lobe and the entire lung. CT findings were compared between asymptomatic and symptomatic cases.
Results: Of 104 cases, 76 (73%) were asymptomatic, 41 (54%) of which had lung opacities on CT. Twenty-eight (27%) cases were symptomatic, 22 (79%) of which had abnormal CT findings. Symptomatic cases showed lung opacities and airway abnormalities on CT more frequently than asymptomatic cases [lung opacity; 22 (79%) vs 41 (54%), airway abnormalities; 14 (50%) vs 15 (20%)]. Asymptomatic cases showed more ground-glass opacity (GGO) over consolidation (83%), while symptomatic cases more frequently showed consolidation over GGO (41%). The CT severity score was higher in symptomatic cases than asymptomatic cases, particularly in the lower lobes [symptomatic vs asymptomatic cases; right lower lobe: 2 ± 1 (0-4) vs 1 ± 1 (0-4); left lower lobe: 2 ± 1 (0-4) vs 1 ± 1 (0-3); total score: 7 ± 5 (1-17) vs 4 ± 2 (1-11)].
Conclusion: This study documented a high incidence of subclinical CT changes in cases with COVID-19. Compared with symptomatic cases, asymptomatic cases showed more GGO over consolidation and milder extension of disease on CT.An earlier incorrect version appeared online. This article was corrected on April 8, 2020.© RSNA, 2020.
2020 by the Radiological Society of North America, Inc.