CT Scan – Abdomen

About a CT scan of the abdomen

The abdomen (tummy) contains many of the body’s main organs, including the liver, gallbladder, pancreas, spleen, kidneys, adrenal glands, stomach and bowel, along with major blood vessels and lymph nodes. A CT (computed tomography) scan uses X-rays and a computer to make detailed cross-section pictures, or “slices”, of these organs, which can be viewed from any angle.

A CT of the abdomen may be used to investigate:

• tummy pain that has not been explained by other tests
• a lump or swelling in the tummy
• abnormal blood tests or ultrasound findings, for example affecting the liver, pancreas or kidneys
• kidney stones and problems with the kidneys
• suspected cancer, or to check how a cancer is responding to treatment
• problems with the major blood vessels, such as an aortic aneurysm

Many conditions affect both the upper and lower tummy, so doctors often request a CT of the abdomen and pelvis together. Your referrer will say which area needs scanning. An ultrasound is often the first test for problems with the liver, gallbladder or kidneys, and MRI can give more detail on some organs without radiation. You can read more in our article on the difference between CT and MRI.

What happens during the scan

You lie on your back on the scanner bed, usually with your arms raised above your head. The bed moves slowly through a short, open ring while your tummy is scanned. The radiographer controls the scanner from the next room, but can see, hear and talk to you throughout. You will be asked to hold your breath for a few seconds at a time. The scan itself takes only a few minutes, although with preparation the appointment usually takes longer.

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 abdomen and pelvis gives a typical dose of about 10 mSv, similar to the natural background radiation you would receive from the environment over about 4.5 years. A scan of the abdomen only is usually a little lower. 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.