Table 1.

CT imaging features of patients with COVID-19

CT Characteristics	Definition
Lobe involvement	Categorized as right upper, right middle, right lower, left upper and left lower lobe involvement
The lung segment involved	Each lung segment was reviewed for GGO, consolidation and reticular types, respectively
Lung involvement	Categorized as unilateral or bilateral lung involvement
Lesion location	Central, lesion located in the interior two-thirds of the lung; peripheral, located in the outer one-third of the lung; Both central and peripheral.
Extent of lesion involvement	Categorized as focal, multifocal, diffuse
Predominantly distribution of opacities	Septal/sub-pleural, involving mainly the sub-peripheral one-third of the lung; peri-bronchovasular, surrounding mainly the peri-bronchovascular bundle; random, without predilection for sub-pleural or peri-bronchovascular regions.
Predominantly CT pattern	GGO pattern, an area of hazy increased lung opacity, within which margins of pulmonary vessels may be indistinct; consolidation pattern, a homogeneous increase in pulmonary parenchymal attenuation that obscures the margins of vessels and airway walls; reticular pattern, a descriptive term usually associated with interstitial lung diseases; mixed pattern, combination of GGO, consolidation, and reticulation.
Interlobular septal thickening	Smooth or irregular
Pleural effusion	Fluid in the pleural cavity
Lymphadenopathy	Arbitrary thresholds for the upper limit of normal of 1 cm in short-axis diameters of mediastinal nodes.