A basic diagrammatic guide to CXR interpretation

1. A Simple Guide to CXR
Interpretation
If you’re struggling to see or differentiate
the abnormal appearances on the
radiographs, take a look at these
diagrams.

2. Pneumothorax
Air in the pleural cavity
Tension Pneumothorax
A complicated pneumothorax where
air enters the pleural cavity but cannot
escape due to the formation of a one-way valve
at the rupture point. Pressure builds
Lung detached
and collapsed
Black, empty
space
Black, empty
space
Mediastinal
shift

3. COAD / Emphysema
Break-down of lung tissue with subsequent loss of alveolar surface area
The lungs then become hyperinflated to accommodate the lost surface area
Insp and Exp become completely reliant on the thoracic cage and abdo muscles
Over-inflated
lungs
Heart appears
Long and thin
Flattened diaphragms

4. Subcutaneous emphysema
Air in subcutaneous layer of skin
Lucent stripes
across soft tissue
Lucent gas collections
in soft tissue
Evidence of cause:
Chest drain

5. Patchy densities
in lungs
Pulmonary oedema – fluid accumulation in lungs
Fluid in alveoli – white
Air still retained in bronchioles – black
Overall – a patchy/fluffy effect

6. Pleural effusion
Excess fluid in pleural cavity
Dense
white
lung
Meniscus
sign
Horizontal fluid level
Blunted costophrenic angle

7. Cardiomegaly (heart enlargement)
Max diameter of heart
exceeds half thoracic
Diameter (in adults)
Cardio:thoracic ratio

8. Atelectasis – alveolar collapse
Think of a sponge with the air squeezed out – this is sort of what’s happened in the lobes of the lung
Right Upper Lobe
Collapse
Elevated horizontal fissure
Triangular density in right apex
Right Middle Lobe
Collapse
Lowered horizontal fissure
Density in middle region with loss
of contrast between the lung and the
Right heart border
Right Lower Lobe
Collapse
Loss of right costophrenic angle

9. Left Upper Lobe
Collapse
A slight increase in density
over the left lung (veil sign)
Left Lower Lobe
Collapse
Loss of left costophrenic angle
A sharp white line behind the heart (sail sign)
Atelectasis

10. Left Upper Lobe
Collapse
A slight increase in density
over the left lung (veil sign)
Left Lower Lobe
Collapse
Loss of left costophrenic angle
A sharp white line behind the heart (sail sign)
Atelectasis