Is there any way to "unopacify" a sinus w/interval opacification? how can one "unopacify" the sphenoid sinus?

Decongestion: A sinus is opacified on a ct scan due to either fluid or soft tissue. This can be due to either an acute infection or chronic infection. The treatment of an acute infection begins with antibiotics and decongestants. A chronic infection is treated also with a prolonged period of antibiotics and nasal steroids. Occasionally oral steroids also. If this does not improve it, surgery can be performed.

Sphenoid sinus : Clearing the sphenoid sinus when it is opacified, may require a combination of medical and surgical therapy depending on the reason the sinus became opacified.

Treat sinusitis: Opacification of a sinus is xray evidence of sinus full of something empty the sinus opacification goes away it can clear itself if you treat the process causing it to fill congestion, infx being most common rarely surgical drainage is indicated.