Incidence of subclinical CT changes high in COVID-19 cases

(HealthDay)—The incidence of subclinical computed tomography (CT) changes in coronavirus 2019 (COVID-19) cases is high, with milder severity seen on CT for asymptomatic versus symptomatic cases, according to a study published online March 17 in Radiology: Cardiothoracic Imaging.

Shohei Inui, M.D., from the Japan Self-Defense Forces Central Hospital in Tokyo, and colleagues describe chest CT findings in an environmentally homogenous cohort of 112 cases of COVID-19 from the Diamond Princess cruise ship.

The researchers found that 73 percent of the cases were asymptomatic, and 54 percent of these cases had lung opacities on CT. The remaining 27 percent of cases were symptomatic, and 80 percent of these cases had abnormal CT findings. Lung opacities and airway abnormalities on CT were seen more frequently in symptomatic versus asymptomatic cases (lung opacity: 80 versus 54 percent; airway abnormalities: 50 versus 18 percent). More ground-glass opacity (GGO) was seen over consolidation (80 percent) among asymptomatic cases, while symptomatic cases more often showed consolidation over GGO (38 percent). In symptomatic versus asymptomatic cases, the CT severity score was higher, particularly in the lower lobes (symptomatic versus asymptomatic cases: right lower lobe, 2 ± 1 versus 1 ± 1; left lower lobe, 2 ± 1 versus 1 ± 1; total score, 7 ± 4 versus 4 ± 2).

"Asymptomatic cases showed more GGO over consolidation and milder extension of lung parenchymal opacities," the authors write.