Table 2 CT findings, extra-pulmonary manifestation and characteristic laboratory findings of COVID-19 and its mimics
| Disease | CT findings | Extra-pulmonary manifestation |
Characteristic Laboratory findings | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Location | GGO | Consolidation | Crazy paving | Nodules | Pleural effusion | Other findings | |||||
| (1) COVID-19 |
Multi-/(less) Unifocal Bilateral Peripheral Posterior or lower zonal | ++++ |
± (more later in the course) | ++ |
(R) (either Tree-in-bud or centrilobular) | (R) |
(T) Vascular dilation and traction bronchiectasis (S)Architectural distortion and subpleural bands (R) bronchial wall thickening, mucoid impaction or LNs |
Abdominal symptoms Acute necrotizing encephalopathy Myocarditis Acute kidney injury |
(- -) Lymphocyte count (++) CRP | ||
| (2) Viral pneumonia | (a) Influenza A, B and C |
Focal Multifocal Diffuse | ++++ | ++ |
++ (Centrilobular) | ++ |
Pseudo-cavitation Pneumatocele LNs ± ARDS | Lymphocytosis or lymphopenia | |||
| (b) Coronaviridae (SARS/MERS) |
Upper and lower resp. infection Multifocal | ++++ | ++ | (R) |
(C) Reticulation (R) Cavitation (R) LNs | ||||||
| (c) HPIV | Multifocal | ++ |
++++ (patchy) |
+ (Centrilobular) | Bronchial wall thickening | ||||||
| (d) Human adenovirus |
Bilateral Multifocal | +++ | Patchy (lobar/segmental) |
++++ (Centrilobular) | ++++ | ||||||
| (e) Herpes viruses |
Multifocal segmental Diffuse | ++++ | + | (C) Multiple hemorrhagic | ++++ | (C) fungal pneumonia |
Gingivostomatitis, pharyngitis and herpes labialis (HSV) | ||||
| (f) Human bocavirus |
Diffuse Along bronchovascular bundles | ++++ |
++++ (patchy) | ++++ | |||||||
| (g) Rhinovirus | Multifocal | ++ | + | (R) | (R) | ||||||
| (h) RSV | Airway centric | ± | ++++ | Bronchial wall thickening | |||||||
| (j) Measles | Peribronchial | Nodular/reticulo-nodular infiltrates | +++ |
Thick interlobular septae (S) Fibrosis (C) Hilar LNs |
Lymphadenopathy gastroenteritis, Encephalitis | ||||||
| (3) Atypical Bacterial pneumonia (Mycoplasma P. and Chlamydia P.) | Uni-/Bilateral | + | + |
+ (Centrilobular/peribronchovascular) | (R) |
Thick bronchovascular bundle (R) atelectasis Chlamydia P. reticular or linear opacity, airway dilatation and emphysema | Fatigue, Malaise | Mildly ( +) or normal WBC | |||
| (4) Pneumocystis jiroveci pneumonia (PJP) |
Central with peripheral sparing (++) in upper lobes |
++++ (extensive in non-HIV) |
+++ (in non-HIV patients) |
++ (in advanced cases) |
+ (solitary/multiple) |
(C) pulmonary cysts spontaneous pneumothorax (R) cancer-like mass (S) interstitial fibrosis | Tachypnea, tachycardia and cyanosis | (++) LDH (not specific) | |||
| (5) Pulmonary edema cardiogenic/non-cardiogenic (ARDS) |
Bilateral Perihilar symmetrical (cardiogenic) | ++++ |
+++ in ARDS (heterogeneous, peripherally and dependent) | ++ |
+++ in cardiogenic edema |
(T) Anteroposterior density gradient Pulmonary cysts lately |
Cardiomegaly Cyanosis, dyspnea tachypnea in cardiogenic edema | ||||
| (6) Hypersensitivity pneumonitis |
Acute: normal or diffuse Subacute: mid/upper lung zone Chronic: peribronchovascular (++) at mid/upper lung zones | +++ |
Acute: centrilobular ground-glass nodules Subacute: poorly defined CL nodules |
Subacute: air trapping (S) Thin walled cysts Chronic: fibrotic changes (septal thickening, traction bronchiectasis, honey combing) | Cyanosis, fatigue, anorexia and weight loss | Non-specific increased ESR and CRP | |||||
| (7) Diffuse alveolar hemorrhage |
Diffuse Patchy Lobular Perihilar Gravity-dependent | +++ | +++ | ± | Hemoptysis, anemia, signs of collagen-vascular disease |
Thrombocytopenia Coagulopathy | |||||
| (8) Pulmonary alveolar proteinosis |
Patchy Subpleural sparing Geographic distribution ++in lower lung |
+++ (T) | No | No | No LNs | Weight loss | Elevated LDH | ||||
| (9) Eosinophilic P. |
Bilateral non-segmental areas Middle and upper lobar predominance | + |
++++ (no subpleural spacing) | + | + | (S) lung reticulations and mediastinal LNs |
Alveolar and blood eosinophilia ++IgE ++ ESR Peripheral thrombocytosis | ||||
| (10) Interstitial lung disease | (A) COP |
Multifocal Subpleural Peribronchial distribution | ++++ | ++++ | + |
(R) masses with regional architectural distortion and interlobular septal thickening.
(T) “atoll sign” | Weight loss, generalized bone aches | ||||
| (B) DAD/AIP |
Symmetric and bilateral Lower lobe predominance Sparing C/P recesses | ++++ |
++ (in the dependent portions) | + |
Later fibrotic phase of DAD Architectural distortion, honeycombing and traction bronchiectasis (similar to UIP) | ||||||
| (C) CTD associated P. | Subpleural and basal predominance | (S) extensive |
(S) Segmental | (S) |
(C) reticular densities, traction bronchiectasis, honey combing and clustered cysts (S) mosaic perfusion, discrete cysts and air trapping | Systemic manifestation according to type of disease | Detected antinuclear antibodies (ANA) and an antibody to ribonucleoprotein (RNP) | ||||