2. Tension hydropneumothorax Air fluid level at right costophrenic angle Deeper right costophrenic angle as compared to the left Contralateral shift of mediastinum

3. ARDS Bilateral diffuse fluffy infiltrates Normal cardiac size Tracheostomy tube Right subclavian central line going inside the right atrium ECG wires

4. Ipsilateral shift of mediastinum and trachea Bronchial cut-off sign suggestive of endobronchial obstruction Rib crowding Loss of volume Obscured right mediastinal and cardiac outline Obscured right hemidiaphragm (silhouette sign) Compensatory hyperinflation of left lung Prominent left pulmonary artery (cardiac output passing through single artery) Right lung collapse - PA view

5. Loss of gradually increasing transradiancy down the spine Only one hemidiaphragm is visible (left) Suspicion of mass in lower lobe with lymph node in mediastinum Right lung collapse – lateral view

6. Ipsilateral shift of trachea, carina and mediastinum Bronchial cut-off sign (left mainstem bronchus) Rib crowding Loss of volume Compensatory hyperinflation of right lung Left lung collapse

7. Airbronchogram sign –Produced as a result of airspace opacification of the lung parenchyma –This results in visibility of the normally invisible black bronchi against a background of white opacification Seen in consolidation and collapse with at least some patency of the bronchus Collapse with airbronchogram

8. Loss of volume on left side Ipsilateral shift of trachea and mediastinum Compensatory hyperinflation of left lung Raised left hemidiaphragm (compare with right) with tenting Haziness over the aortic knuckle (silhouette sign) Left upper lobe collapse – PA view

9. Oblique fissure displaced anteriorly Opacification anterior to the oblique fissure Left upper lobe collapse – Lateral view

10. Loss of volume on right side Opacification of right upper lobe Transverse fissure raised Right hilum is also raised Right upper lobe collapse - PA view

11. Oblique fissure displaced anteriorly Transverse fissure pulled upwards Opacification with loss of volume of right upper lobe Right upper lobe collapse – lateral view

12. Loss of volume on left side Ipsilateral shift of the heart Both hila are at the same level (left hilum has come down) Double opacity behind the heart Outline of left hemidiaphragm is obscured (silhouette sign) Left hemidiaphragm is raised (watch the gastric bubble) Left lower lobe collapse – PA view

13. Loss of gradually increasing transradiancy down the spine One hemidiaphragm is clearly visible Oblique fissure is displaced posteriorly Left lower lobe collapse – Lateral view

14. Multiple small millet sized nodules throughout both lung fields Miliary shadowing

15. Mediastinal widening in upper part mediastinum Loss of volume on left side Double opacity behind the heart Left hemidiaphragm not visible Heart shifted to the left side Mediastinal mass with left lower lobe collapse

16. Fungus ball with surrounding rim of air Aspergilloma

17. Left sided pleural effusion Associated lobulated pleural thickening No shift of mediastinum due to encasement by mesothelioma Mesothelioma

18. Cat under the rug appearance indicative of pleural based origin Angle between chest wall and opacity is obtuse (>90o) Pleural based mass

19. Bilateral hilar lymphadenopathy Right paratracheal strip enlargement Bilateral infiltrates involving predominantly the mid zones Sarcoidosis

20. Left sided apical pneumothorax Visceral pleural line is clearly visible –There should be no lung markings distal to the visceral pleural line Pneumothorax

21. Complete opacification of right hemithorax without significant contralateral shift of mediastinum Absence of shift is indicative of concomitant collapse Usually a sign of malignancy Effusion with collapse