What is a CT scan of the sinuses?
A CT scan of the sinuses is a special type of computed tomography that produces images of the cavities around the nose. These hollow spaces, which include the frontal sinuses, maxillary sinuses, ethmoid cells, and sphenoid sinuses, are filled with air and connect to the nasal cavity.
The scan produces detailed cross-sectional images in which even the smallest changes can be seen. Unlike a standard X-ray, a CT scan can show not only bones but also tissue, mucous membranes, and fluid collections in great detail. This is why it is used particularly when routine examinations do not produce clear results.
When is a CT scan of the sinuses carried out?
A CT scan is often arranged when there are persistent symptoms in the nose or sinus area and there is a suspicion of chronic inflammation or other structural changes. It is also frequently performed before a planned sinus operation to assess the anatomy accurately.
Typical reasons for a CT scan of the sinuses include recurring or long-lasting sinus infections, facial pain, a feeling of pressure behind the forehead, restricted nasal breathing, or unusual findings on an X-ray or during an examination by an ear, nose, and throat (ENT) specialist.
In some cases, the CT scan also helps to identify polyps, cysts, thickened mucous membranes, or anatomical variations that are disrupting the normal ventilation of the sinuses.
How does the scan work?
The CT scan itself usually takes only a few minutes and is completely painless. You lie on a table that slowly moves through the opening of the CT scanner. During this time, X-rays produce thin cross-sectional images that are used to create a three-dimensional picture of the head area.
For a CT scan of the sinuses, contrast dye is usually not needed, as the structures can be seen clearly without it. The radiation exposure is relatively low, but it is higher than with a standard X-ray, which is why the scan is used selectively and only when medically necessary.
What can the CT scan show?
A CT scan is particularly good at identifying inflammatory processes, swollen mucous membranes, bony changes, or fluid collections in the sinuses. Blockages in the connecting passages to the nose, known as ostia, also become visible. These are often the reason why mucus cannot drain properly, which encourages chronic inflammation.
The CT scan can also provide evidence of polyps, cysts, fungal infections, or tumour-like changes. After facial injuries, such as a fracture of the nasal bone or the eye socket, a CT scan is also used to assess the exact extent of the damage.
What happens after the CT scan?
The CT images are assessed by a specialist in radiology. The written report is usually passed on to the treating GP, ENT specialist, or clinic. Depending on the result, a decision is made together on whether treatment with medication is sufficient or whether a surgical procedure is necessary, for example to remove polyps or to widen the ventilation passages.
In any case, the CT scan provides a precise basis for further decisions, particularly when symptoms have been present for a long time or keep returning.
