What are the critical features to be assessed at CT?

Etiology: Paranasal sinus disease? Dental disease?
Extent: Is it anterior or posterior to the orbital septum? If posterior, it is orbital cellulites. If anterior, it is periorbital cellulites.
Presence of complication:
Subperiosteal abscess (fluid in medial orbit adjacent to medial rectus muscle)
Orbital vein or cavernous sinus thrombosis