X-rays and scans
X-rays and scans are usually the first types of tests your doctor will send you for, as they are non-invasive, mostly painless and very effective in both diagnosing and determining the stage of many cancers. If you are pregnant, breastfeeding or diabetic, let your doctor and technician know before you have an X-ray or scan.
Barium is a white liquid that is ingested or inserted. It coats the walls of your gullet, stomach, or bowel, and can be seen very clearly on X-rays, which can identify any abnormal changes in those three areas. There are two main types of barium X-rays:
A barium enema is a special X-ray of the bowel. To get clear X-ray pictures your bowel must be empty, so you will be given some medicine to help clear your bowel and may also be asked to not eat or drink before or on the day of the test.
During the test, a nurse will ask you to lie on your side on a special table. A thin rubber tube will then be gently put into your back passage, and the barium mixture will be poured through the tube into your bowel. You will be asked to hold on to the barium mixture while the X-rays are being done, and may have to change positions depending on the different X-rays needed.
The procedure is slightly uncomfortable but not painful, and you will be able to go home afterwards. Barium may cause constipation and your first couple of bowel movements will appear white in colour, but these will both cease once the barium is out of your system.
A barium swallow is a special X-ray of the gullet (oesophagus) or stomach. Before the test, you will be asked to not eat or drink for 6 hours beforehand.
In the X-ray department you will be asked to drink a white chalky liquid that contains barium. The barium will flow down your oesophagus and the X-ray will be taken.
A barium swallow lasts about 15 minutes, does not hurt and you will be able to go home immediately afterwards. Some people may experience nausea or constipation after the test, but this should go once the barium passes through your system.
Bone scans are very sensitive and can find cancer cells before they show up on an X-ray.
Before the scan, a very small amount of a mildly radioactive substance, or radionuclide, is injected into a vein, usually in your arm. You will then have to wait for up to 3 hours for the radionuclides to travel through your body.
How bone scans work
When the radionuclides have passed through your body, you’ll be asked to lie down on an X-ray table. A camera will then scan your entire body. Abnormal bone absorbs more radionuclides than normal bone, so it will show up as darker patches on the scan.
The scan lasts for up to an hour and you’ll be able to go home immediately afterwards. The amount of radioactivity used in these scans is very low and safe and will disappear from your body within a few hours.
What cancers do Bone scans check for? They’re good for checking any bone cancer, or for a cancer that may have spread to your bones from somewhere else in your body.
CT scans (or CAT scans) take X-rays from different angles around your body, creating a series of cross-section pictures or ‘slices’. Putting these slices together can help build a very accurate picture of the location and size of any tumours, and how close other internal organs may be. They can be used to look at any part of your body including your brain, lungs or bowels.
Before the scan, you may be asked to not eat or drink for up to 4 hours. You may also be given a special drink or an injection with a safe, high-contrast material to help certain areas of your body show up more clearly.
How CT scans work
You’ll be asked to lie on an X-ray table and to remain as still as possible. The table will then slide forwards and backwards through the doughnut-shaped CT scanner until all the pictures are taken.
CT scans do not hurt, although some people may feel a bit claustrophobic when passing through the scanner – you will be able to communicate with the radiographer via an intercom or buzzer if you need to. CT scans take around half an hour per scan and most people will be able to go home immediately afterwards.
What cancers do CT scans check for? Because a CT scan can look at your entire body, they check for all types of cancers.
MRI uses magnetic energy to build up a picture of the tissues inside your body and can be used to scan any part of your body including your brain, lungs, bowels, etc.
Before the scan you may be asked not to eat or drink beforehand, and you will need to remove any hair clips, jewellery, prosthetics or anything else that might contain metal. Those who have certain medical devices in their body, like a pacemaker or metal pin, are not suitable for the test. If you have a nicotine patch or other drug patch you may be asked to remove it to prevent a skin burn.
How MRI scans work
You may get an injection before your scan that will allow certain areas of your body to show up better. During the scan you’ll be asked to lie on a table and to stay as still as possible, but you will be able to breathe as normal. The table will then move either all or part of the way into the tube-shaped scanner. The scanner is very noisy and will make a constant clanging sound so the radiographer will give you earplugs or headphones. You will also have an intercom or buzzer so you can alert them if you need to.
MRI scans don’t hurt although some people may feel a bit claustrophobic when passing through the scanner – you can ask for a mild sedative ahead of time if needed. Each scan lasts for around 30 minutes and most people will be able to go home immediately afterwards.
What cancers do MRI scans check for?
An MRI is good at detecting many different types of cancers. Sometimes your doctor will use a CT scan and an MRI scan to build a clearer picture of your organs.
A PET scan uses a low dose of radioactive sugar to measure the activity in your cells and can give your doctor more information about a cancer already found in your body. It is also used to diagnose or determine the stage of a number of different cancers.
How PET scans work
Before the scan, you may be asked not to eat or drink anything for a few hours. When you arrive for your scan, you will be given an injection of radioactive sugar, usually into your arm. You’ll then be asked to lie down for around an hour so that the sugar can travel to all the cells in your body, so it’s a good idea to bring some music to listen to. As cancer cells absorb large amounts of the sugar, there will be more radioactivity where the cancer cells are found.
The scan itself doesn’t hurt and may take up to 1 hour. PET is safe to use and there are no side-effects.
An ultrasound uses sound waves to build up a picture of your internal tissues, and can be used to scan any part of your body.
There is usually no preparation required for an ultrasound unless you are having a rectal ultrasound to examine your prostate. In this case you may be given some medicine to make sure your bowels are clear before the scan.
How ultrasounds work
When you arrive you may change into a hospital gown. You’ll then be taken to the scanning room and you’ll be asked to lie down, usually on your back, and a gel will be spread over the area to be scanned. A small device like a microphone is moved back and forth over your skin to take the scan. This device makes sound waves that are changed into a picture on a computer.
If you are having a rectal or vaginal ultrasound, the technician will use a different type of microphone that can be inserted. They may have to rotate or move the microphone to scan everything, which may be slightly uncomfortable but shouldn’t hurt.
Ultrasounds can take from 10 minutes to half an hour and you can go home immediately afterwards.
Call our National Cancer Helpline
Freephone 1800 200 700 to talk to a specialist cancer nurse
It's open Monday-Thursday from 9am to 7pm and Friday from 9am to 5pm