Concept of eFAST

Radiographic findings in an eFAST (Extended Focused Assessment with Sonography for Trauma) allow an emergency physician to decide whether a patient has pneumothorax, hemothorax or pleural effusion. 

IMPORTANT SIGNS

Stratosphere sign  in an eFAST examination indicates pneumothorax. This finding in the M-mode tracing as pleura and lung being indistinguishable as linear hyperechogenic lines and is fairly reliable for diagnosis of a pneumothorax.

Seashore sign is another eFAST finding usually in the lungs in the M-mode that depicts the echogenicity of the lung abutted by the linear appearance of the visceral pleura. This sign is a normal finding. In absence of a seashore sign or presence of a stratosphere sign, pneumothorax is likely.