COVID-19 imaging: Diagnostic approaches, challenges, and evolving advances

Table 1 Three main chest radiographic scoring systems use for coronavirus disease-2019 and their characteristic features

	Chest Radiography Scoring Systems for COVID-19
Characteristics of Chest Radiography Scoring Systems	Severe Acute Respiratory Infection[48]	Radiographic Assessment of Lung Edema[49]	Chest X-ray Score[51]
Division of Lungs	None	2 lungs	6 zones (3 zones each lung)
Methodology of Score Calculation	Entire lungs scored as one	Each lung scored and totaled	Each zone scored and totaled
Characteristics Scored	Various radiographic findings	1GGOs or consolidation	Various radiographic findings
Scoring Scale	1 = normal; 2 = patchy/hyperinflation/bronchial wall thickening; 3 = focal consolidation; 4 = multifocal consolidation; 5 = diffuse alveolar change	1 ≤ 25%; 2 = 25%-50%; 3 = 50%-75%; 4 ≥ 75%	0 = no abnormalities; 1 = interstitial infiltrates; 2 = interstitial (predominant) & alveolar infiltrates; 3 = interstitial & alveolar (predominant) infiltrates
Designed Specifically for COVID-19 Disease	No	No	Yes

¹Ground glass opacities. Modified based on study from Wasilewski et al[47]. COVID-19: Coronavirus disease-2019; GGO: Ground-glass opacities.