A specialist doctor may ask you to have one or more scans to help explain your symptoms. If you have a brain tumour, a scan may show what kind of tumour it is and help your doctor decide on the best treatment for you.
You are most likely to have one of two types of scan:
Other scans include:
Computed Tomography (CT scan)
How does it work?
This method uses X-rays that are taken from many different directions and angles. This makes it possible for the computer to create detailed pictures of your brain. It will produce a series of pictures that represent what each layer of your brain looks like.
To show or hide more about CT scans, click here.
How do I prepare for the scan?
You may be asked not to eat or drink for some time before the scan. You will have to take off any jewellery as it may interfere with the scan and you may be asked to undress or put on a hospital gown.
What will happen?
You will have to go to the hospital to have your CT scan. The radiographer will explain the procedure. This is a good time to ask any questions.
The CT machine looks like a big doughnut with a hole in the middle and a couch in front of it for you to lie on. The couch moves in and out of the tunnel so that lots of pictures can be taken from different angles.
The doctor may want to scan other parts of your body, including your chest, stomach, or spine. This is to see if there are any other abnormalities or to find out if your tumour could have spread from cancer in another part of the body.
The scan takes about 30 minutes, although a lot of this time is spent setting it up so that you are in the right position. You will be asked to lie as still as possible throughout the scan.
You will be able to talk through an intercom to the radiographer during the scan. You will normally be allowed to go home after the scan.
An appointment will be made to discuss the results later with your specialist.
What will it feel like in the tunnel?
CT scans are not noisy, painful or dangerous.
However, some people find being in the tunnel a bit claustrophobic (closed in). If you think this might happen to you, it is best to tell the radiographer first.
If you worry you will not be able to keep still, talk to your doctor in advance and they may be able to give you some medicine to help you relax.
In some cases, a dye may be injected into your vein before the scan. This contrast medium helps to show the outline of the tumour more clearly. The dye only remains in your blood for a short period of time before being removed by the kidneys.
What are the pros of having a CT scan?
CT scans are capable of picking up most tumours. They are widely available in hospitals so it may be possible for you to have one done quite quickly.
What are the risks of having a CT scan?
You are exposed to a quite a lot of radiation during the scan. It is not enough to do you harm, but a doctor will not suggest a scan unless he/she thinks there is a reasonable chance that you have a brain tumour.
So, if you are asked to have a CT scan, it is because your doctor has decided the benefits are bigger than the risks. It will help him/her decide on and start treatment as soon as possible.
A few people are allergic to the contrast dye injected before the scan. The specialists are aware of this and will be able to treat you if you are affected.
Magnetic Resonance Imaging (MRI)
How does it work?
MRI is a scan using magnetism to build up a picture of the inside of the head.
The scanner will almost certainly show up a brain tumour. It will show up clearly each different type of tissue within the brain so it can give some idea about what a tumour is made of.
To show or hide more about an MRI scan, click here.
What will happen?
You will have to go to the hospital to have your MRI scan. The radiographer will explain the procedure and you should ask them any questions you may have.
The MRI machine looks like a tube with a couch in front of it for you to lie on. The couch moves in and out of the tunnel so that lots of pictures can be taken from different angles inside the tube. The doctor may want to scan other parts of your body, including your chest, tummy (abdomen), or spine. This is to see if there is anything abnormal or to find out if the tumour has spread from some other part of the body.
The procedure may take between 30 and 90 minutes. You will be asked to lie as still as possible throughout the scan to get accurate images. You will be able to talk through an intercom to the radiographer during the process. You will normally be allowed to go home after the scan. An appointment will be made to discuss the results later with your specialist.
How do I prepare for the scan?
You will have to take off any jewellery and you may be asked to undress or put on a hospital gown.
The radiographer will ask you lots of questions to ensure that you do not have any metal inside your body as metal will affect the scan.
For instance, a pacemaker, a contraceptive coil (IUD), cochlear implant (hearing aids), or metal plates or pins that were put in during previous operations. You will not be allowed to have an MRI if you have any of these metal implants as metal interferes with the machine.
Having an MRI is not harmful or painful. However, they do make a very loud noise. You may be able to listen to some music through headphones. Bring your own music in case it can be used. Keeping your eyes closed may help you to relax.
Some people find being in the tunnel claustrophobic (closed in). If you think, this may happen to you, it is best to tell the radiographer before.
If you worry you will not be able to keep still, talk to your doctor in advance and they may be able to give you some medicine to help you relax.
You may be asked not to eat or drink for some time before the scan.
In some cases, a dye called gadolinium is injected into your vein before the scan. This contrast medium helps to see the outline of the tumour more clearly. The dye only remains in your blood for a short period of time before being removed by the kidneys.
What are the pros of having an MRI scan?
Unlike CT scans, MRI does not use any radiation. This makes it safer for children and pregnant women. MRI is better than CT scans at picking up small tumours and those that are at the back or base of the brain.
They show more clearly how far the tumour has grown into other tissues as well as being able to see the tumour from many angles. This helps to plan the best way to remove it surgically.
What are the cons of having an MRI scan?
It is more expensive and there is a longer waiting list to use MRI scanners. They are noisy and the process often takes longer.
What is the risk of having an MRI scan done?
MRI is very safe, as long as there are no metal implants in your body.
A few people are allergic to the dye injected before the scan. The allergic reaction most often starts with sweating, a rash and difficulty with breathing. The specialists are aware of this risk and will know what to do if this does happen.
Abdominal ultrasound and chest X-ray
Your doctor may ask you to have a scan of your tummy (abdomen) and a chest X-ray in order to check whether you have cancer anywhere else in your body.
To show or hide more about ultrasound and x-rays, click here.
In adults, secondary cancer is cancer which started in another part of the body. Secondary brain cancer is much more common than primary cancer that starts in the brain itself.
Ultrasound uses sound waves to build up a picture of the area being scanned. It is completely painless and only takes a few minutes.
X-rays use radiation to take a picture of the body. The amount of radiation is quite small and fairly safe. But radiation can be harmful so doctors will try to keep the number of x-rays that you have to as few as possible. The amount of radiation your body absorbs depends on the type of x-ray used and which part of the body is involved.
PET scan
PET stands for Positron Emission Tomography. This is a fairly new type of scan to show up where the tumour is. It is only available at a few hospitals. If your specialist wants you to have a PET scan, you may have to travel to another hospital.
To show or hide more about PET scans, click here.
You will be given a small amount of mildly radioactive glucose through an injection (usually in the arm). The small amount does not harm you. The scanner traces the glucose as it spreads through your body. Sometimes, the scan is combined with a CT scan or X-ray to create a 3-D view of the glucose in your body.
The brain uses up the glucose and the scan measures how quickly this happens. The tumour normally absorbs more of the glucose and the extra radioactivity in the tumour shows up on the scan. A PET scan may help to tell whether a tumour is growing and whether it is cancerous (malignant) or benign.
After the injection is given you may be asked to lie in a dark room with your eyes closed. You will then be taken to the scanning room and asked to lie on a couch with the scanning ring around you.
SPECT scan
SPECT stands for Single Photon Emission Computed Tomography. It is similar to a PET scan, but uses much simpler equipment to get information about chemicals in the brain tumour.
To show or hide more about SPECT scans, click here.
You will be given an injection of a very small amount of a radioactive chemical. This is really a tiny amount and does not harm you. The radioactive chemical circulates in your blood to your brain and shows up the brain tumour on the scanner.
