CT Scan of the Head: About This Test

Skip to the navigation

What is it?

A CT (computed tomography) scan uses X-rays to make detailed pictures of your body and the structures inside your body. A CT scan of the head can give your doctor information about your eyes, the bones of your face and nose, your inner ear, and your brain.

During the test, you will lie on a table that is attached to the CT scanner. The CT scanner is a large doughnut-shaped machine.

Why is this test done?

A CT scan of the head can help find the cause of symptoms that may mean you have a brain injury or bleeding inside your head. It can also find a tumour and damage caused by a stroke and help find the best treatment for the cause of a stroke.

How can you prepare for the test?

Talk to your doctor about all your health conditions before the test. For example, tell your doctor if:

  • You are or might be pregnant.
  • You are allergic to any medicines.
  • You have diabetes.
  • You take metformin.
  • You are breastfeeding.
  • You get nervous in confined spaces. You may need medicine to help you relax.

What happens before the test?

  • You may have to take off jewellery, glasses, or hearing aids. Wear comfortable, loose-fitting clothes.
  • You may have contrast material (dye) put into your arm through a tube called an IV. Contrast material helps doctors see specific organs, blood vessels, and most tumours.

What happens during the test?

  • You will lie on a table that is attached to the CT scanner. Straps will hold your head still but your face will not be covered.
  • The table will slide into the round opening of the scanner. The table will move during the scan. The scanner moves inside the doughnut-shaped casing around your body.
  • You will be asked to hold still during the scan. You may be asked to hold your breath for short periods.
  • You may be alone in the scanning room, but a technologist will be watching you through a window and talking with you during the test.

What else should you know about the test?

  • A CT scan does not hurt.
  • If a dye is used, you may feel a quick sting or pinch when the IV is started. The dye may make you feel warm and flushed and give you a metallic taste in your mouth. Some people feel sick to their stomach or get a headache.
  • If you breastfeed and are concerned about whether the dye used in this test is safe, talk to your doctor. Most experts believe that very little dye passes into breast milk and even less is passed on to the baby. But if you prefer, you can store some of your breast milk ahead of time and use it for a day or two after the test.
  • There is a small chance of getting cancer from some types of CT scans. The risk is higher in children, young adults, and people who have many radiation tests. If you are concerned about this risk, talk to your doctor about the benefits and risks of a CT scan and confirm that the test is needed.

How long does the test take?

  • The test will take about 30 to 60 minutes. Most of this time is spent getting ready for the scan. The actual test only takes a few minutes.

What happens after the test?

  • You will probably be able to go home right away.
  • You can go back to your usual activities right away.
  • Drink plenty of fluids for 24 hours after the test if dye was used, unless your doctor tells you not to.

When should you call for help?

Watch closely for changes in your health, and be sure to contact your doctor or nurse call line if you have any problems.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse call line if you are having problems. It's also a good idea to keep a list of the medicines you take. Ask your doctor when you can expect to have your test results.

Where can you learn more?

Go to https://www.healthwise.net/patientEd

Enter Y628 in the search box to learn more about "CT Scan of the Head: About This Test".