What is the role of imaging in diagnosing orbital cellulitis?

• A. Imaging is unnecessary.
• B. CT/MRI is required to confirm orbital involvement and detect complications.
• C. X-ray of the chest is sufficient.
• D. Ultrasound of the abdomen is most helpful.

Answer: (B)

Imaging is used to confirm that the infection has spread behind the orbital septum (orbital cellulitis) and to look for complications. A CT scan of the orbits with contrast, often with sinus imaging, is the first-line test because it quickly shows orbital soft-tissue involvement, any abscess formation (subperiosteal or orbital), and related sinus disease that often serves as the source. If there’s concern for deeper or more subtle involvement—such as optic nerve or intracranial extension—MRI provides superior soft-tissue detail. The results from imaging guide management: presence of orbital involvement or an abscess typically prompts aggressive IV antibiotics and possible surgical drainage, while limited, nonorbital infection may be managed differently. Imaging of the chest or abdomen does not inform orbital infection and wouldn’t be helpful in this diagnosis.