Tips and Pearls for Chest X Ray part II

- Air fluid level

• Air fluid level in esophagus = esophageal stasis
• Intrapulmonary cavity with air fluid level - upper walls must be visible
• Hydropneumothorax = indistinct upper walls with different 'shape' of air fluid levels in PA and lateral view ( lower level can be outlined by the curved minor fissure )

- Thymoma can regularly metastasize to pleural layers

- Any opacity in diaphragm may arise below

- Lymph node with hypodense center - think about TB

- Ivory vertebrae ddx - adult - malignancy, lymphoma, Paget's disease of bone; kids - lymphoma, neuroblastoma, osteoblastoma, Ewing's sarcoma, osteosarcoma

- When the undersurface of the rib is eroded, the mass arises from the structure below the rib when it is found beneath the eroded rib

- There are 3 knobs on PA view in normal person - aortic knob, pulmonary arch and LV

• In MS, left auricle can be seen between pulmonary arch and LV
• A bulging pulmonary arch suggests PAH

- 3 ddx of bulging pulmonary arch

• Enlarged hilum + abrupt tapering of the vessels - PAH due to lung diseases or heart failure
• Enlarged hilum + increased vascularity seen in PA film - left to right shunt
• Normal or decreased vascularity without enlarged hilum - congenital pulmonic stenosis

- Kerley lines - A line, B line and C line

• Look for Kerley lines when u see reticular pattern 
• If CHF can be excluded, another ddx for Kerley line is lymphagitis carcinomatosis

- Aspiration due to achalasia normally goes to right apical lobe !!

- Upper lobe redistribution in hemithorax - CHF, MS or PE

- Hematoma can be suspected by seeing increased density of the mass in CT scan ( same as blood in LV )

- ABPA - tree in a bud pattern, can cause mucous impaction and lobar collapse

- PseudoPTX - the vessels will cross the pseudopleural line !!

- Oreo cookie sign - first layer - lung, second layer - fluid, third later - epicardial fat pad, diagnostic of effusion

- Lytic lesion in lung - MM, renal and thyroid cancer, blastic lesion ( Ivory rib ) - prostate cancer

- Air crescent sign - aspergilloma; water lily sign - hyatid cyst

- Know how to differentiate bullae vs pneumothorax

- Double density sign on aortic arch suggests a posterior mediastinal mass hiding behind the aorta

- Bronchiectasis can be cystic or cylindrical lesion

- Air below right diaphragm - pneumoperitoneum, pneumobilia ( Rigler's triad ), emphysematous cholecystitis and Chilaidit's syndrome