Normal Chest

1. Tracheal air column
2. Carina
3. First Rib; Count down from here for diaphragmatic level
4. Peripheral 1-2 cm of lung fields have no markings except
5. The minor fissure
6. The top of the diaphragm is near the medial half of its length. The top of the right diaphragm is normally at a level between the anterior end of the anterior 6th rib and the anterior 7th rib. The level of the diaphragm can also be reported with reference to the posterior Aab: on full inspiration, the domes of the diaphragm are seen overlying the posterior aspects of the 10th and 11th Aab.
7. Left diaphragm is lower in 90-95% of normals by roughly half an interspace (2% greater than 3cm)
8. Inferior margins of the posterior Aab are often ill-defined
9. Anterior mediastinal line (apposed visceral and parietal pleura of the two upper lobes)
10. Superior vena cava shadow blends imperceptibly into the shadows of the neck
11. Region of the azygous vein (vein not visible). A caliber greater than 7mm is suggestive raised venous pressure, or enlargement of adjacent node. Normal may be up to 10mm.
12. Right descending pulmonary artery. Not greater than 16mm in men, 15mm in women.
13. Pulmonary arteries and veins. Hard to distinguish the two. Arteries are vertical and medial and emerge from the hilum. Veins are horizontal and lateral and run toward the left atrium below the hilum.
14. Border of the right atrium
15. Inferior vena cava
16. Aortic arch
17. Left pulmonary artery
18. Border of the left ventricle
19. Descending aorta
20. Fat density lines in the intermuscular fascial layer