Further tests

Your doctor will select the most suitable tests for your situation. Some people have these while they are still in hospital. But they can also be done as an outpatient and you can go home shortly after the test is finished.

Possible tests include:

  • Blood tests and sometimes a chest x-ray – These are done to check your general health.
  • Brain MRI – Magnetic resonance imaging scans use magnetism to produce a detailed picture of the brain.
  • CT scan – This takes a series of x-rays so to create a three-dimensional image of the brain.
  • Biopsy – A small part of the tumour is removed to find out the type of tumour you have.
  • PET scan – This measures the activity of cells in different parts of the body and can be used to find out if a tumour is cancerous or non-cancerous.
  • SPECT scan – This is similar to a PET scan but looks at the flow of blood through the brain.
  • Lumbar puncture – A hollow needle is inserted between the bones of the lower back to collect cerebrospinal fluid (CSF) and look for tumour cells.
  • Angiogram – This uses a dye injection and X-rays to observe the blood vessels that supply the brain tumour.

Blood tests and chest x-rays

A blood test cannot diagnose a brain tumour but you may have blood tests to check your general health. You might also have a chest x-ray to make sure your lungs are working well.

Brain MRI (magnetic resonance imaging) scan

This may be the first test you have. The test uses magnetism to build up a detailed picture of your brain and central nervous system. The scanner is a powerful magnet so you may be asked to complete and sign a checklist to make sure it’s safe for you. The checklist asks about any metal implants you may have, for example a pacemaker, surgical clips, bone pins, etc. You should also tell your doctor if you’ve ever worked with metal or in the metal industry as very tiny fragments of metal can sometimes lodge in the body. If you do have any metal in your body it’s likely that you won’t be able to have an MRI scan. In this situation another type of scan can be used.

Before the scan, you’ll be asked to remove any metal belongings including jewellery. You will be given an injection of dye into a vein in the arm, which doesn’t usually cause discomfort. This is called a contrast medium and can help the images from the scan to show up more clearly. During the test you’ll lie very still on a couch inside a long cylinder (tube) for about 30 minutes. It’s painless but can be slightly uncomfortable, and some people feel a bit claustrophobic. It’s also noisy, but you’ll be given earplugs or headphones. You can hear, and speak to, the person operating the scanner.

A specialised MRI scan called magnetic resonance angiography (MRA) may sometimes be done to look at the blood vessels of the brain.

Occasionally doctors use a scan called a magnetic resonance spectroscopy (MRS) to help diagnose a brain tumour by looking at the chemicals activity of the tumour.

CT (computerised tomography) brain scan

A CT scan takes a series of x-rays, which build up a three-dimensional picture of the brain. The scan takes only a few minutes and is painless. It uses a small amount of radiation, which is very unlikely to harm you and will not harm anyone you come into contact with. You may be given injection of a dye, which allows particular areas to be seen more clearly. This may make you feel hot all over for a few minutes. It’s important to let your doctor know if you are allergic to iodine or have asthma, because you could have a more serious reaction to the injection. You’ll probably be able to go home as soon as the scan is over.


The doctors may need to take a small part of the tumour (a biopsy) to find out exactly what type of tumour you have.

We have more details about the procedure in the biopsy section.

PET (positron emission tomography) scan

A PET scan uses low-dose radioactive glucose (a type of sugar) to measure the activity of cells in different parts of the body. It may help to find out whether a tumour is growing and whether it is cancerous (malignant) or non-cancerous (benign).

A very small amount of a mildly radioactive substance is injected into a vein, usually in your arm. A scan is then taken a couple of hours later. Cancer cells are usually more active than surrounding tissue, and show up on the scan. Not all hospitals have PET scanners, so if you need one you may have to travel to another hospital.

A PET scan isn’t routinely used to diagnose a brain tumour, but it may help to tell whether a tumour is growing and whether it is cancerous (malignant) or benign.

SPECT (single photon emission computerised tomography) scan

This test is similar to a PET scan but it looks at the blood flow through the brain. It’s done in the same way as a PET scan.


An angiogram uses an injection of a dye and x-rays to see the blood vessels in the brain that supply the tumour. The dye is injected through a thin, flexible tube (catheter) that is inserted into an artery in the groin, arm or neck. A series of x-rays are taken. Angiograms can be done as part of a CT or MRI scan.

Lumbar puncture

A lumbar puncture is sometimes carried out after ependymoma is diagnosed to look for tumour cells in the cerebrospinal fluid (CSF).

Your doctor uses a local anaesthetic to numb the lower part of your back and then passes a needle gently into the spine. They then take a small sample of CSF to be checked for tumour cells.

A lumbar puncture is usually done as an outpatient and it only takes a few minutes.

A lumbar puncture cannot be done if there is raised intracranial pressure, so it will probably be done later on in your treatment.

Waiting for test results

Waiting for test results can be a difficult time. It may take from a few days to a couple of weeks for the results of your tests to be ready. You may find it helpful to talk with your partner, family or a close friend. Your specialist nurse can also provide support. You can also talk things over with one of our cancer support specialists on 0808 808 00 00.

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