CT Scan – Neck (Soft Tissue)

About a CT scan of the neck

The neck contains many important structures packed closely together: the throat (pharynx), voice box (larynx), windpipe and gullet, the thyroid and salivary glands, major blood vessels, and chains of lymph nodes. A soft tissue neck CT (computed tomography) scan uses X-rays and a computer, usually with an injection of contrast dye, to make detailed cross-section pictures of these structures from the base of the skull to the top of the chest.

A neck CT may be used to look at:

• neck lumps and swollen lymph nodes that have not gone away, usually after an ultrasound
• head and neck cancers, such as cancers of the mouth, throat and voice box, to see how far they have spread and plan treatment
• infections, such as an abscess behind the tonsils (quinsy) or deeper in the neck
• salivary gland problems, including stones and swelling
• the neck after surgery or treatment for cancer

An ultrasound is often the first test for a neck lump, and can be used to guide a needle biopsy. MRI gives more detail of some areas, such as the tongue, salivary glands and back of the nose, without radiation; see neck (soft tissue) MRI. For the bones of the neck, a cervical spine CT is used instead. Your referrer will say which scan is best.

What happens during the scan

A small cannula is placed in a vein in your arm. You lie on your back on the scanner bed with your head resting in a cradle and your arms by your sides. The bed moves through a short, open ring while your neck is scanned. The radiographer controls the scanner from the next room, but can see, hear and talk to you throughout. You will be asked not to swallow or cough while the pictures are taken, and sometimes to say “eee” or puff out your cheeks to show the throat more clearly. The scan itself takes less than a minute.

For some CT scans, an injection of contrast dye is given through a small cannula in a vein, usually in your arm or hand, to make blood vessels and organs show up more clearly. CT contrast contains iodine. As it goes in you may feel warm and flushed, notice a metallic taste, or feel as if you are passing urine; these feelings pass within a minute or two. Allergic reactions are uncommon, and you may be asked to wait for up to 30 minutes afterwards. Where contrast is needed, it is charged separately.

Is CT safe?

CT uses X-rays, which are a type of ionising radiation. A CT of the neck gives a relatively low dose, but the thyroid gland lies in the scan area, so the scan is only done when it is likely to help. If you may need radioactive iodine treatment for a thyroid condition, tell your specialist, as iodine contrast can delay it. The risk from a single scan is very small, and every CT scan is checked by a radiologist or radiographer to make sure the benefit of the scan outweighs the risk, as required by the Ionising Radiation (Medical Exposure) Regulations. If you have had other CT scans recently, tell us when you book.