Imaging Case of the Week 505 Answer

The facial x-ray shows ‘black eyebrow’ sign. This finding suggests presence of orbital air. There is also a fracture of the supero-medial wall of the right orbit.

Orbital emphysema causing black eyebrow sign is an indirect sign of orbital blow out fracture and sometimes can be the only finding visible on a plain x-ray. Collection of air is seen as a lucency in the superior aspect of orbit.

Scrutinize inferior (maxillary sinus), medial (ethmoid sinus) & superior wall of orbit (frontal sinus) when orbital emphysema is the only plain x-ray finding in a patient with blunt injury to the face.

Further reading : https://emedicine.medscape.com/article/383739-overview#a2