Table 3.

Semi-quantitative analysis of lung for prognostic features

Reference	Author	Year	CT findings	Results
[44]	Baysal	2021	Higher incidence in ICU patients (39/405): - GGO (87.2%) - consolidations (79.5%) - air bronchogram (53%) - reticular pattern (48.7%) - pleural effusions (31%) - number of involved lobes (median IQR 5)	Higher median CT score in ICU patients: - median IQR 13 vs. 4 - AUC – ICU: 0.71–0.75 Higher frequency in ICU patients: - older age (median age 65) - comorbidities: hypertension (57%), chronic kidney disease (17%)
[45]	Ruch	2020	Significantly higher incidence in severe patients (95/572): - GGO (98.9%) - consolidations (74.7%) - pulmonary embolism (16.8%) - bilateral involvement (100%)	Association between lung involvement > 50% and early severe disease (ICU or death) OR: 2.35 Higher frequency in severe patients: - male sex (80%) - dyspnea (86.3%) - lower SpO2 (median 90%) - abnormal laboratory tests: higher CRP (median 154 mg/L), higher neutrophil count (median 6375 cells/mm3), lower lymphocyte count (median 740 cells/mm3), higher lactate (median 1.2 mmol/L)
[46]	Luo	2021	Significantly higher incidence in ICU patients (64/496): pulmonary opacity score ≥ 41% (59%)	Association between pulmonary opacity score ≥ 41% and ICU admission: OR 2.35
[47]	Lieveld	2020	CO-RADS scoring system: ≥ 4 as the optimal cut-off for discriminating between a positive and a negative PCR AUC of 0.912	Higher median CT score in ICU patients: 14.8 vs. 5.5 – discharge home and 9.4 – hospital admission Association between CTSS and ICU admission - OR: 1.23 - AUC – ICU: 0.81 Higher frequency in severe patients: - comorbidities: CVD (29.1%), COPD (20%), diabetes (23.7%), current malignancy (18.2), hypertension (36.3)
[48]	Buttner	2020	Higher incidence in ICU patients (18/28): - consolidation (94.4%) - pleural effusions (16.7%)	Higher percentage of affected lung area in ICU patients: - 26% vs. 7.8% - 10% increase in the affected lung parenchyma area - increased the instantaneous risk of intubation (HR 2.00) and ICU need (HR 1.73) - AUC – ICU: 0.856 Higher frequency in ICU patients: - younger age (median age 58.2) - female sex (57%) - obesity (22.2%)
[49]	Hosse	2021	Higher incidence in ICU patients (137/265): - extensive consolidation (13.1%) - extensive GGOs (27.0%) - posterolateral involvement (37.2%)	Higher percentage of affected lung area in ICU patients: - 25.5% vs. 5.4% - 10% increase in the affected lung parenchyma area - increased the instantaneous risk of intubation (HR 1.35) and ICU need (HR 1.68) - AUC – ICU: 0.735 Higher frequency in ICU patients: - older age (median age 75.0) OR – ICU: 1.27 - male sex, OR – ICU: 1.20 - chronic lung disease, OR – ICU: 1.68
[50]	Li	2021	Higher incidence in severe/critical patients (35/53): - peak of CT scores in the third week (vs. the second week of moderate patients) - higher overall lung involvement score (from the second to the fourth week)	AUC – severe/critical disease: overall lung involvement score (2nd week) 0.747, ground glass opacity score (2nd week) – 0.744 AUC combined models – severe/critical disease: overall lung involvement score (2nd week) + CURB65 0.808, overall lung involvement score (2nd week) + qSOFA 0.810 Higher frequency in ICU patients: - cough - higher qSOFA and CURB65 at admission
[51]	Shayganfar	2021	Significantly higher incidence in ICU/death (38/176): bilateral lung involvement (97.4%)	Higher median CT score in ICU /death: - 14.39 vs. 9.53 - AUC – ICU: 0.732 - OR – CT score ≥ 11: 4.38 OR – ICU/death: 4.38 – age ≥ 60, 2.78 – O2 saturation of ≤ 90.5%
[52]	Mozafari	2021	Significantly higher incidence in ICU patients (32/213): - consolidation (100%) - crazy paving (71.87%) - linear opacities (78.1%) - air bronchogram (78.1%) - bilateral distribution (100%) - peripheral and central involvement (96.75%) - pleural effusion (15.6%) - higher number of involved lobes (87.5% – ≥ 5), mainly RUL (96.9%), RML (90.6%), LUL (96.9%)	Higher median CT score in ICU patients: - median 17.34 vs. 6.78 - home discharge and 10.66 - hospitalized - deceased patients after ICU admission (23/32): higher age – median 62.4 vs. 47.77, higher score – median 20.78 vs. 16.00 Higher frequency in ICU patients: - male sex (71.9%) - non pulmonary pre-existing conditions (43.75%) - lower SpO2 (median 86.78%) - dyspnea (100%) - higher temperature (median 37.02) - abnormal laboratory tests: higher ESR (median 68.50 mm/h), higher WBC (median 10.02 103/μL), lower lymphocyte count (median 11.22%)
[53]	Davarpanah	2020	Significantly higher incidence in ICU patients (45/228): - consolidation (31%) - pleural effusion (26%) - bronchial wall thickening (42%) - peripheral and central distribution (24%)	Higher median CT score in ICU patients: - 11.9 vs. 8.2 - OR – total CT score (per 1 score increase): 1.13 Higher frequency in ICU patients: - older age (median age 65), OR – ICU (per 1-year increase): 1.05 - lower O2 saturation, OR – ICU (O2 saturation ≤ 88%): 3.97
[54]	Salahshour	2021	Significantly higher incidence in ICU patients (72/739): - total pulmonary involvement score (median 15.1) and density index (median 3.3) - peripheral, pleural-based distribution of lesions (41.2%) - bilateral lesions (92.6%) - crazy paving - pleural effusion (bilateral – 16.2%, unilateral 10.3%) - crazy paving (36.8%) - parenchymal band (39.7%)	AUC PI (cut-off 8) – ICU: 0.77 Predictive model (age ≥ 53, SpO2 ≤ 91, PI score ≥ 8) – ICU: sensitivity 40.98%, specificity 89.11%, NPV 89.63%, accuracy 81.95% Significantly higher frequency in ICU patients: - older age (median age 60.6) - higher respiratory rate (> 24) - lower O2 saturation (< 93%) - higher PCR - higher mortality (27.8%)