Hi,
"Soft Tissue Attenuation" the sinus is made of bone (hard tissue), but its linned by a mucus membrane (soft tissue) and attenuation is a radiological term meaning a change from base line indicate increased water content most likely due to an inflammation.
Sphenoid sinusitis could be the worst night mare for an ER physician or a neurologist, because it could present in different ways, the physical examination is not helpful, and it warrants aggressive therapy
Though, its anatomical location is dangerous, but as long as the CT did not say it has a thin wall (can be extremely thin, or even a thin mucosal barrier) you should not worry,
UNLESS,
1-you have had several episodes of sinusitis
2-or have low immune system, diabetes,
3- or the fever /headache are not subsiding , or developing new symptomes in the eye or the face
A repeat CT (A GOLD STANDARD) or MRI (NEVER A ROUTIN X- RAY) anyway is advised after therapy to see the resolution