The Asthma Center

CT scan of sinuses

CT (computerized tomography) scan of the sinuses is the best radiologic technique for evaluation of sinusitis. CT scans provide excellent definition of the sinus cavities, nasal turbinates and osteomeatal complexes. It also provides a roadmap for surgery. The CT reveals the underlying bone surrounding the sinuses, evidence of infections, obstruction and complications. Two views are commonly performed – coronal and axial. The coronal view divides the sinuses into the front and back with vertical imaging cuts through the sinuses. The axial view scans the area from the front toward the back using horizontal imaging cuts. CT scans of the sinuses are usually performed without radiocontrast material (dye) and are best at outlining the bony and soft tissue structures of the sinuses.

CT scan findings consistent with sinusitis often include:

  • Complete or partial sinus opacification: loss of air space within the sinus due to tissue swelling and/or pus accumulation
     
  • Mucosal thickening: swelling or heaping up of the normal lining of the sinuses
     
  • Air fluid level: fluid collection (usually pus) within the sinuses producing a
     
  • discrete layering effect resulting in a line separating air from fluid
     
  • Blockage of the osteomeatal complex


CT scans can also identify complications from sinusitis, such as infection extending into the tissue in or around the eyes, brain, or surrounding bone. CT scans of the sinuses may show other abnormalities such as sinus polyps, cysts, or other growths.