left apical cap

 Q: "Left apical cap" sign in blunt thoracic trauma is suggestive of damage to which organ?

A) lung

B) pericardium

C) thyroid

D) aorta

E) clavicle

Answer: D

A chest x-ray is usually the first imaging available to clinicians after trauma presentation. Although signs on CXR are not conclusive but can be suggestive of underlying organ damage. Blunt aortic injury (BAI) can be presumed from CXR. Few suggestive signs of BAI are 

•  Wide mediastinum 
•  Obscured aortic knob 
• Left "apical cap" sign i.e., (ie, pleural blood above the apex of left lung) 
• Left hemothorax 
• Nasogastric tube deviated towards the right 
• Trachea deviated towards the right 
• Right mainstem bronchus deviates downward

'Left apical sign' can be seen in other non-traumatic situations too like old age, pleural scarring, radiation fibrosis, Pancoast tumor, lymphoma, and abscess.

#trauma

References:

1. Kirwadi A, Pakala VB, Kumar DS, et al Apical left extrapleural cap: an early and important sign on chest radiographs. Emergency Medicine Journal 2008;25:819.. 

2. Kram HB, Appel PL, Wohlmuth DA, Shoemaker WC. Diagnosis of traumatic thoracic aortic rupture: a 10-year retrospective analysis. Ann Thorac Surg 1989; 47:282. 

3. Ekeh AP, Peterson W, Woods RJ, et al. Is chest x-ray an adequate screening tool for the diagnosis of blunt thoracic aortic injury? J Trauma 2008; 65:1088.