Further tests for brain tumours
This page is about further tests you might have if you have been diagnosed with a brain tumour. There is information about
Further tests for brain tumours
If you have been diagnosed with a brain tumour, you may need further scans or tests. These find out more about the tumour, including exactly where it is and how big it is, to help your doctor decide on the best treatment. You may have the following scans
MRI scans create pictures of body structures using magnetic fields and give clear pictures of the brain and spinal cord. An MRI scan called magnetic resonance angiography (MRA) shows the blood vessels in the brain. Magnetic resonance spectroscopy scans (MRS) look at chemicals in the tumour. functional MRI (fMRI) takes the scan while you do things like move your hand, speak or read.
PET scans show up the rate of activity of body tissues. You have a small amount of radioactive glucose as an injection. The scan measures how quickly the brain uses the glucose in different areas. It can help to show if a brain tumour is non cancerous (benign) or cancerous (malignant).
SPECT scans get information about chemicals in the brain tumour. You have an injection of a very small amount of a radioactive chemical, which circulates in your blood to your brain and shows up the brain tumour on the scanner.
Other tests include
- Surgical biopsy – taking a small sample of the tumour to examine under a microscope
- CT scan of the chest and abdomen – checking whether cancer is anywhere else in the body
- Angiogram – looking at the blood circulation in the brain
- Myelogram – using a dye and X-rays to show fluid circulation around the spinal cord
- Lumbar puncture – taking a sample of cerebrospinal fluid for testing
- Neuroendoscopy – under general anaesthetic, drilling a hole in the skull and into the fluid filled spaces in the brain (the ventricles) to relieve pressure or take a biopsy or fluid sample
After your tests
You will probably feel anxious while waiting for your test results. It may help to talk to a friend or relative about your feelings. Or you may want to contact a support group to talk to someone who has been through a similar experience.
You can view and print the quick guides for all the pages in the Diagnosing brain tumours section.
These tests help the doctor to find out exactly what type of brain tumour you have. They also help the doctors to find out how exactly where it is and how it is. This information is important to help the doctors know which is the best treatment.
MRI is a type of scan that creates pictures of body structures using magnetic fields. MRI usually gives the clearest scan of the brain and spinal cord. You usually have an injection of a dye, called contrast medium, to make the MRI scan clearer.
Specialised MRI scans called magnetic resonance angiography (MRA scans) can show the blood vessels in the brain. Magnetic resonance spectroscopy (MRS scans) look at chemicals in the tumour.
Another type of MRI scan is called a functional MRI (fMRI). During this scan the doctor will ask you to do things like move your hand, speak or read. These scans are used to help plan surgery when the tumour is close to an area controlling one of these functions.
PET scans are not available at all hospitals. So you may need to travel to another hospital to have one. PET scans can show up the rate of activity of body tissues. You have a small amount of radioactive glucose as an injection and the glucose is taken up in the brain. The brain uses up the glucose and the scan measures how quickly this happens in different areas.
The speed of glucose use by the brain helps to show if a brain tumour is non cancerous (benign) or cancerous (malignant). After brain tumour treatment, PET scans can also sometimes show up whether changes on other scans are due to tumour or to scar tissue.
We have detailed information about what having a PET scan is like.
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. As with a PET scan, you have an injection of a very small amount of a radioactive chemical. This does not harm you. The radioactive chemical circulates in your blood to your brain and shows up the brain tumour on the scanner.
Taking a sample of tissue is the only sure way to diagnose many brain tumours. Looking at the cells under a microscope is the only guaranteed way to identify the type of brain tumour and grade of the tumour.
For some brain tumours, you have a biopsy as the first part of an operation to remove all or part of your tumour. For others, you may just have a biopsy and then go onto have other treatment such as radiotherapy.
In some cases it is not possible to have a biopsy because the tumour is in an area of the brain that is too difficult to operate on. This may be because the tumour is close to major blood vessels or is in an area of the brain that controls vital functions in the body.
Your doctor may ask you to have a CT scan of your tummy (abdomen) and chest. The scan is to check whether you have cancer anywhere else in your body. It builds up a picture of body structures by taking a series of X-rays.
In adults, cancer that has spread to the brain (secondary brain tumour) is much more common than cancer that started in the brain (primary brain tumour). So it is sensible for your doctor to check.
In the section about cancer tests we have information about having a CT scan.
An angiogram examines the blood supply to the area being scanned. Angiograms are not done very often for brain tumours these days but are are sometimes used when a tumour is growing very deep inside the brain. They are also an important test for meningiomas and some other types of brain tumour. They give surgeons the following information.
- Which blood vessels are supplying the tumour
- If the tumour is attached to any major blood vessels in the brain
You usually need to go into hospital overnight. You will need a sedative or sometimes a general anaesthetic. You have the angiogram in the X-ray department. First, you have a tube (catheter) put into a blood vessel in your groin. The doctor injects a dye that shows up on X-ray into the tube. After a minute or so, the dye will have circulated through your bloodstream into the blood vessels into your brain. Your surgeon will look at your brain on an X-ray screen to see exactly whether the tumour is close to the blood vessels.
Depending on the type of brain tumour you have, your surgeon may then inject a substance to block the blood vessels that carry blood to the tumour. This helps to shrink the tumour before you have surgery to remove it. This procedure is called embolisation or interventional angiography. There is a small risk of a stroke from this procedure. But this risk is usually small compared to the benefit of treating the tumour. Before you have this treatment, your specialist will explain it fully to you. You will be able to ask questions or talk through any worries that you have.
A myelogram gives pictures of the spinal cord. It is only used for people who cannot have an MRI scan, for example if they have a pace maker fitted.
First you have a lumbar puncture. Then the doctor injects a dye into the area around the spinal cord. This is the space that the cerebrospinal fluid flows through. The dye spreads through this fluid. Then the doctor takes X-rays. If a tumour is blocking the flow of the fluid, the dye cannot get past it. So the position of the tumour will show up on the X-rays.
A lumbar puncture is only used for certain types of brain tumour that can spread within the central nervous system. The test involves getting a sample of cerebrospinal fluid and examining it for cancer cells.
Doctors can't always do this test on people with brain tumours. Sometimes, the pressure inside the brain and spinal canal (the intracranial pressure) is too high and to do a lumbar puncture would be dangerous. We have detailed information about having a lumbar puncture.
Children usually have a sedative or a short general anaesthetic to have this test. There are two main reasons for this. It is very important to keep very still and they may find the test upsetting.
You have this test under general anaesthetic. The doctor carefully drills a 2cm hole into the skull. They put a fine tube called a neuroendoscope into the hole and into the fluid filled chambers of the brain (the ventricles).
You may have this test to
- Take a biopsy of a tumour that is in or near the ventricles
- Take fluid samples for tests
- Drain fluid if too much has built up and caused an increase in pressure (hydrocephalus)
If you have the test to drain fluid it is called a third ventriculostomy.
Your doctor or nurse will ask you to go back to the hospital when your test results have come through. This is bound to take a little time, even if only a few days. You are likely to feel very anxious during this time.
While you are waiting for results it may help to talk to a close friend or relative about how you feel. Or you may want to contact a cancer support group to talk to someone who has been through a similar experience. Look in our general cancer organisations section for information about people who can offer support. Our counselling section has details of counselling organisations who can help you to find a counsellor in your area.
If you want to find people to share experiences with online, you could use Cancer Chat, our online forum.
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