1. AFAMS Residency Orientation April 16, 2012
Basics of Chest X-Ray
AFAMS Residency Orientation
April 16, 2012

2. Outline CXR Basics Types of CXR Obtaining Images
PA vs. AP Films
Obtaining Images
Systematic method to reading CXR
Common Signs
Examples

3. Chest X-ray (CXR) Basics
A standard chest X-ray consists of a
PA Image
Lateral Image
Images read together
AP for supine patients
Lots of information available on a CXR
Be systematic with your reading
Always compare to prior studies if possible

4. Basics of X-Rays X-Rays are part of the light spectrum
Unlike visible light, x-rays pass through the human body
Pass through lungs without much interference
Difficult to pass through bones
Place film cassette on other side of patient and capture the shadow

5. Basics of X-Ray
Organs absorb X-rays differently and thus their shadow on the film is different
Bone: high absorption (film appears white)
Tissue: moderate absorption (film appears grey)
Air/Lungs: little absorption (film appears black)

6. Types of CXRs PA and Lateral Supine AP Patient facing cassette
X-ray 6 feet away
Supine AP
X-ray 40 inches away
Magnifies anterior structures and pulmonary vasculature
101 cm
1.83 m

7. Comparing Chest X-rays ProtocolsAP
Preferred method
Note heart enlarged, lung fields not as clear

8. PA Image
PA Film
Read as if patient is facing you (Patient’s left side is on the right of the X-ray)

9. Lateral Image Obtained with patient’s left side against the cassette.
Minimizes heart silhouette magnification

10. Assessing Film Technique
Inspiration
Penetration
Rotation

11. Inspiration Image should be at full inspiration
Diaphragm at level of 8-10 rib
Allows reader to see intrapulmonary structures
Poor Inspiration mimics RML Infiltrate
Same patient with proper inspiration

12. Penetration Amount of radiation required for a quality image
PA film: should barely see thoracic spine disc spaces
Lateral: spine should appear darker as move cadually
Examples of adequately penetrated images

13. Penetration
Overpenetrated
Underpenetrated

14. Rotation Patient should be flat against the cassette
Rotation of the patient will alter appearance of mediastinum
Observe rotation by comparing location of clavicular heads
Should be equal distance from spinous process of thoracic vertebral bodies

15. Rotation
Normal
Rotated to the Right

16. Mass vs. Infiltrate
Mass
Infiltrate

17. Lobes and Fissures: PA Film
A: Minor Fissure between RML and RLL
B: Upper and lower boundaries of major fissures

18. Lobes and Fissures: Lateral
B: Major Fissure L Lung
A: Minor Fissure R Lung
B: Major Fissure R Lung

19. CXR Anatomy

20. CXR Anatomy

21. How to Read an X-Ray Part 1
Patient Data (Name, history, age, sex)
Technique (PA vs. AP, rotation, penetration, etc)
Trachea: midline or deviated, any masses?
Lungs: masses, infiltrates?
Costophrenic angles should be sharp (if not = effusions)
Silhouette signs, air-bronchograms, pulmonary edema
Pulmonary vessels: enlarged?

22. How to Read an X-Ray Part 2
Hilar Region: masses or lymphadenopathy
Heart: enlarged, abnormal shape
Pleura: effusion, thickening, calcification
Bones: fractures or masses
ICU Films: looks for line and tube placement

23. How to Read an X-Ray Part 3
It is best to focus on a small area of the film and then scan rather than look at the whole film at once

24. Signs: Silhouette Sign
Loss of lung/soft tissue interface caused by mass, fluid, or infiltrate in the normally air filled lung
Commonly applied to heart, aorta, chest wall, and diaphram borders with lung
Location of silhouette sign helps to localize pathology
Lose Right Heart and Lung border = RML

25. Signs: Air Bronchogram
Tubular outline of an airway made visible by filling of the surrounding alveoli by fluid or inflammatory exudates
Causes
Pulmonary edema
Lung Consolidation
Severe Interstitial Disease
Neoplasm

26. Signs: Solitary Pulmonary Nodule
Can be innocuous or potentially fatal lung cancer
Always compare to prior films for growth
Nodules with irregular borders are suspicious

27. Conclusions Lots of information in a chest x-ray
Always read the film in the same order
Never skip to the most prominent abnormality, you will miss a small (but potentially important finding)
Compare to priors if possible
We will finish with some examples of common pathology

28. Examples: Atelectasis
Collapse or incomplete expansion of alveoli
Causes:
Endobronchial lesions (mucous plug or tumor)
Extrinsic compression (mass, lymph node)
Peripheral compression (pleural effusion)
Linear density on CXR

29. Examples: Pulmonary Edema
Cephalization of pulmonary vessels (arrow)
Kerley B Lines
Peribronchial cuffing
“Bat Wing” Appearance
Increased Cardiac Size (arrow)

30. Examples: Pneumonia Airspace disease and consolidation CXR Findings
Airspace opacity
Lobar consolidation
Interstitial opacities

31. Differentiating Atelectasis from Pneumonia
Volume Loss
Associated ipsilateral shift
Linear, wedge shaped
Apex at hilum
Air bronchograms
Normal or increased volume
No shift
Consolidation, air space process
Not centered at hilum
Air bronchograms

32. Examples: TB
TB can be seen as consolidation, cavitation, fibrosis, adenopathy, or pleural effusion depending on stage of infection

33. Examples: Pleural Effusions
Fluid in Costophrenic Angle
Blunting of Costophrenic Angles

34. Examples: Pneumothorax (PTX)
Air inside the thoracic cavity but outside the lung
PTX appears as air without lung markings in least dependent area of chest

35. Examples: Hemopneumothorax
Lung
Air
Fluid

36. Examples: Interstitial Lung Disease
Hazy ground glass opacification
Volume Loss
Linear opacities bilaterally
“Honeycomb lung”

37. Examples: COPD and Emphysema
Diffuse hyperinflation
Flattened diaphragms
Increased retrosternal space
Bullae

38. Examples: Rib Fractures
Can you find the rib fracture?

39. Examples: Pericardial Effusion

40. Examples: Hiatal Hernia
Gastric Bubble

41. Hilar Enlargement
Enlarged Pulmonary Artery
Hilar Adenopathy