2.3 Data collection and analysis
We reviewed the clinical charts of all the pediatric patients for
demographic information, symptoms, date of symptom onset, admission
date, discharge date, dates and results of nucleic acid tests for
COVID-19, and other identified concurrent infectious pathogens.
Two radiologists (WX and ZL with 12 and 18 years of experience,
respectively) independently reviewed the chest CT images on PACS, only
decision reached in consensus was reported. The initial CT images were
stratified into one of two groups: normal or abnormal group. The CT
images in the abnormal group were further assessed for imaging features
including: (a) unilateral or bilateral distribution, (b) lobes involved,
and (c) lesion characteristics. Lesion characteristics were
subcategorized into: (a) ground-glass opacity, (b) consolidation, (c)
nodule, and (d) thickened interlobular septa.
The involvement of lung was quantified according to a previously
published paper, which had applied it in adults with COVID-1916. We divided each
lung into upper zone (above the carina), middle zone, and lower zone
(below the inferior pulmonary vein). And each zone was scored for
percentage of lung involved on a scale of 0-4 (0 for 0% involvement; 1
for less than 25% involvement; 2 for 25% to less than 50%
involvement; 3 for 50% to less than 75%; 4 for more than 75%
involvement). Overall CT score of lung involvement was the summation of
scores from all six lung zones.