Week 4 - CXR Interpretation

Question 1

When is a CXR required?

Answer 1

• in an accident
• respiratory admission to hospital
• suspected respiratory infection

Question 2

1. Labels and Orientation
   - Identify where the labels are
   - How do you interpret orientation

Answer 2

Labels
- Name, date, and time // usually in the top corners

Orientation
- Interpret as if you’re looking at the patient

Question 3

2. Orientation Marker

Answer 3

Often has a (L) for Left and (R) for Right
- Heart should always be on the L side

Question 4

3. Projection

Answer 4

Determine whether the X-Ray was from an AP or PA projection
- if “mobile” assume AP projection

Question 5

4. Exposure

Answer 5

Exposure of an X-Ray is your ability to see what you’re intending

If X-Ray is too white = underexposed/increase density e.g heart
If X-Ray is too black = overexposed/decrease density e.g air

Nb: Good exposure should be able to see the spinous processes to T4

Question 6

5. Patient Position

Answer 6

What position is the patient in?
- Erect
- Supine
- Lateral Decubitus

Nb: if clavicles are equal distance from spinous processes = pt. is centred/not leaning

Question 7

6. Inspiratory vs. Expiratory Phase

Answer 7

During the inspiratory phase, you should be able to count:
- first 6 ribs anteriorly
- first 9 ribs posteriorly

Question 8

7. Soft Tissues

Answer 8

> Breast Tissue
Swelling
Subcutaneous Emphysema (air where soft tissue should be)
Air under the diaphragm

Question 9

8. Bony Structures

Answer 9

> Fractures
Joints
Thoracic Shape
Vertebral Column
Osteoporosis

Question 10

9. Mediastinum

Answer 10

• Heart
  > SVC, (R) and (L) Atrium, (L) Ventricle, and Aorta
  > less than 1/2 diameter of the chest
• Hilum
  > Bronchi, Arteries, Veins, Lymph Nodes
• Trachea
  > Midline, bifurcation should be visible

Question 11

10. Diaphragm

Answer 11

• Outline should be clear
• Right higher tan left
• Costophrenic and cardiophrenic angle
• Elevated?
• Flattened?

Question 12

11. Lung Fields

Answer 12

• Translucency Symmetrical
• Lung markings evenly spaced and all the way out to the edge of the film
• Horizontal fissure approx. 4th IC space

Question 13

12. Silhouette Sign

Answer 13

> Obstructing of anatomical border by contact of infiltrate
Directly correlates with area of pathology

Question 14

13. Attachments

Answer 14

> ETT/Trache
- T4 or 3-4 cm above carina

> Central Venous Catheter
- Just above RA in SVC

> Swan Ganz Catheter
- In PA outside RV

> ICC
NGT
ECG Dots

Question 15

What 3 type of infiltrates can be identified as lung pathologies?

Answer 15

> Interstitial
Pleural
Alveolar

Question 16

How do you identify Interstitial Infiltrates?

Answer 16

> Increased hilar markings
Finger-like Projections
Parabronchial Cuffing
Kerley B lines