1. Principles and Interpretation of
Chest X-Rays

2. Before reading a chest X-ray
• Demographics data
– Check the patient name
– Age
– Patient identification number
– Check the date on which the chest X-ray was taken

3. Technical quality
• Orientation – Right / Left
• Penetration -
• Projection
• Degree of inspiration
• Rotation

4. Orientation

5. Penetration
• Normal penetration
• Under penetration
• Over penetration

6. Criteria for:
Adequately exposed x-ray
 Tracheal shadow is seen
till T4.
 No vertebral bodies are
seen behind cardiac
shadow.
 Appears greyish.
Over exposed x-ray
 Appears highly translucent.
 Vertebral bodies seen
behind cardiac shadow.
 Prominent
bronchovesicular markings.

8. Projection
• AP view
• PA view
• Lateral view
• Lateral Decubitus view

9. AP view

10. PA view

11. How to differentiate AP and PA view
PA AP
• Medial end of clavicle
overlies posterior end of 4th
rib. – Horizontal
• Medial border of scapula –
Out of lung field
• Vertebral bodies – Inverted
V shape
• Heart – well defined
borders
• Clavicles are projected
above the ribs. – Oblique
• Scapula overlies the lung
field
• Vertebral bodies –
Rectangle shape
• Heart – Enlarged and ill
defined borders

13. Lateral view

15. Lateral Decubitus view

16. Degree of inspiration

18. Rotation

19. Diaphragm

20. CP
angles

21. • Different tissues in our body absorb X-rays at
different extents:
– Bone- high absorption (white)
– Soft tissue - somewhere in the middle absorption
(grey)
– Fat – (Dark grey)
– Air- low absorption (black)

22. • Look at the Bones
• Soft tissue
• Look at any artifacts
• Look at the costophrenic and cardiophrenic
angles
• Look at the diaphragms
• Look at the borders of lung field

23. • Mediastinum
– Look at the trachea
– Look at the heart borders
• Look at the hilum
• Look at the lung fields (lung parenchyma )

30. Normal ratio < 0.5

32. Lobes

38. Clinical interpretation
of X- rays

40. By: Tejas R. Chokshi

43. • Most common view used in ICUs?
• PA
• AP
• Lateral
• Decubitus

44. • In PA view, medial end of clavicle lies against
which rib?
• 1st rib
• 2nd rib
• 3rd rib
• 4th rib
• 5th rib

45. • Which dome of the diaphragm is seen higher
in Chest X Ray?
• Right
• Left
• Both
• None

46. Identify View of x-ray
a. AP
b. PA
c. Lateral
d. None

47. • In normally exposed X Ray fat looks…
• Grey
• Dark grey
• White
• Black

48. THANK
YOU

71. Any Questions?

72. Thank you