Sinuses may be the cause - cured once

I had BO for nearly 2 years now and at one point it was really horrible I had to go get it checked out. I didn't tell the doctor I had BO but I complained of bad breath and told he diagnosed me with PND and gave me a sinus steroid. I took it one night and to my surprise the next day I got no reactions as far as I can remember. I can't remember if it came back after or not whilst on the corticosteroid. I finally told him I had BO when it came back and he did a CT scan of my nose and foudn out I had infammed turbinates. Went to a specialsit (otolaryngolosit) and he said it could be due to mucus congestion. IS it possible that this odor could be due to the sinuses? I can't smell a thing but others do, my family members also can't smell it. If you have BO that you can't smell but others notice (except possibly family memebrs) go take a CT scan, it will not hurt believe me!