Figure 1: 53-year-old patient with leukemia prior to radiation therapy.
a) Conventional radiograph of the paranasal sinuses; soft tissue swelling within the right maxillary sinus without air-fluid level.
b) CT of the paranasal sinuses of the same patient. The CT was performed 2 hours after plain radiographs. CT shows sinusitis of the sphenoid sinus not detectable on the radiographs.
c) CT does not confirm sinusitis of the right maxillary sinus.