Does a ct scan of the sinus show sinus infection or just structural abnormalities?

Both and more.: Ct scans are great for showing anatomy and disease states. Infection, trauma, tumors, and anatomic variants of normal can be seen. The sinuses have normal drainage pathways that can be seen as open or obstructed by infections, tumors, and deviations from normal anatomic form. Such deviations can lead to recurring/chronic sinusitis that may require surgical cure.