SET T0012 -
Emergency Department. All CXRs.

• Left lower zone shadowing consistent with pneumonia in this patient.
• Left heart border ill defined - indicating that the pneumonia is situated in the upper lobe (Silhouette Sign).

See : The Chest X-Ray : A Survival Guide : Pages 45-50

Initial observations:

• Shadowing over right mid and lower zones.
• The heart appears " enlarged ".

BUT:

• The anterior aspects of all of the ribs show a very steep downward angulation - often (but not always) seen in patients with a severe Pectus Excavatum.
• A Pectus will often squeeze the AP diameter of the heart and also displace the heart to the left side. This can produce a spurious appearance of cardiomegally.
• Similarly, the displacement of the heart can mean that the right heart border is effaced - because it is projected over the spine . The right lower zone shadowing is also spurious - in the sense that it is simply related to the  pectus with bunching up of the chest wall soft tissues.

Next steps: 1) examine the patient; 2) if any persisting concern regarding a hidden pneumonia - obtain a lateral CXR.

Numerous features are there to be recognised. All are left sided. Listed here (not in the order of clinical importance):

• Clavicle fracture.
• Fracture of the scapula (inferior to the glenoid labrum).
• Several rib fractures.
• Pneumothorax.
• Also - evidence of a haemopneumothorax.
• Collapse of the lower lobe.
• Surgical emphysema is also observed ( in the left side of the neck and in the chest wall ).

[ The shape of the head of the left humerus is not indicative of a posterior dislocation. The left arm is simply held in passive internal rotation and this accounts for the " light bulb " appearance ].

Light bulb appearance ?? . . .

See : Accident & Emergency Radiology : A Survival Guide (3rd edition) : Pages 88 and 92-94

Observations:

• A very large right pneumothorax. Indeed, no lung is evident on this side; the pleural space is massively distended with air.
• Heart displaced to the left side.
• Depression - and flattening - of the right dome of the diaphragm.

Conclusion: Tension pneumothorax.

See : The Chest X-Ray : A Survival Guide : Pages 100-102