Finding the right tests…
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Finding the right tests…
CT Scan
Chronic sinusitis that keeps coming back, or a sinus surgery your doctor is planning, is usually evaluated with this version first - a scan of your sinuses that doesn't need a contrast injection. RadiologyInfo.org describes non-contrast CT as the standard test for recurrent acute or chronic sinusitis, and calls it the most reliable way to see whether your sinuses are blocked. Surgeons also use these images beforehand to map out your sinus anatomy, since no two people's sinuses are shaped quite the same way, and that mapping helps plan the safest route during endoscopic sinus surgery. Contrast is only added if your doctor suspects the infection has spread beyond the sinuses themselves.
This scan images your sinuses - the air-filled spaces around your nose and eyes - along with the bone between them, without a contrast injection. It shows whether the sinuses are blocked, inflamed, or thickened, and maps their anatomy in detail for a doctor planning sinus surgery.
RadiologyInfo.org notes that CT of the sinuses doesn't commonly require contrast material, and describes the non-contrast version as the imaging of choice for recurrent acute or chronic sinusitis. It's considered the most reliable way to see whether your sinus passages are obstructed.
- Fluid or thickened membrane lining the sinuses - Blockage in the drainage pathways between the sinuses and nasal cavity - The bony structure separating each sinus, including variations in your own anatomy - Signs of inflammatory disease
Endoscopic sinus surgery works through narrow passages close to the eyes and base of the skull, so surgeons rely on this scan beforehand to map the exact anatomy they'll be working around. That planning is part of why it's ordered even when surgery, not just diagnosis, is the goal.
Contrast-enhanced CT becomes the imaging of choice specifically when a complication like periorbital or orbital cellulitis - infection spreading into the tissue around the eye - is suspected, since contrast helps distinguish a straightforward infection from one that has spread beyond the eyelid.
Ask your doctor or the centre which version applies to your case.
Contrast isn't usually needed to see whether your sinuses are blocked or inflamed, which is why RadiologyInfo.org lists the non-contrast version as standard for chronic sinusitis. It still shows the bone and soft tissue of the sinuses in detail.
Endoscopic sinus surgery works through narrow spaces close to the eyes and base of the skull, so surgeons use these images beforehand to map your specific anatomy. It helps plan a safer route during the operation.
Contrast is used if your doctor suspects infection has spread beyond the sinuses, such as toward the eye socket or the brain. That's a different, more urgent situation than routine chronic sinusitis.
This page is general information about the test, not medical advice. Your own report's reference ranges apply — please discuss your results with your doctor.
Yes, CT uses X-rays, so there is some radiation exposure. Tell your doctor or technologist if there's any chance you're pregnant.
It shows whether your sinuses are blocked or inflamed, which supports a diagnosis your doctor makes alongside your symptoms and exam. It's considered the most reliable imaging test for confirming obstruction.
Preparation is usually straightforward, but ask your doctor or the centre about specifics for your appointment, including any chance of pregnancy.
It can show an abnormal growth, though your doctor may add contrast or order an MRI if more soft-tissue detail is needed to characterize it.