After 4 rounds of antibiotics, predinsone, ct scan still showed mucus in my maxillary sinuses. now i'm feeling pressure again. did it never clear up?

Probably not: Sounds like the return of symptoms may indicate the problem is still there, but may have been suppressed by the antibiotics. Sinuses can also take a long time to heal. May be good to be evaluated by an ENT surgeon if the problem persists after treatment. Hope this helps!

Sinusitis: You will probably need a repeat ct scan to see what is going on if it has been a while An ENT doctor can scope the nasal cavities to look and see if there is an active infection. The ENT doctor can also go over the scans with you to review what are the next steps. Good luck and feel better. Most of the time additional therapy is need and not always surgery.

Many reasons.: (1)blockage of the ostiomeatal complex preventing sinus drainage. (2)possibly allergic fungal sinusitis which would not respond to antibiotics (3) Impaired immune system which can't kill off the bacteria. Agree that you should consult an ENT.