Brain tumour

A guide for patients and carers

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Tests and investigations for brain tumour

After the onset of symptoms of a brain tumour, most people would usually see their GP who then refers them to a local hospital, or directly to a neuroscience centre, for tests and investigations.

Doctors will ask you questions to help them form a detailed medical history and you will have a physical examination as part of the assessment of your symptoms. You will have an initial brain scan (either a CT scan or an MRI scan; see below).

CT scan

A CT (Computerised Tomography) scan is possibly the first type of brain scan you will have. It is a special type of X-ray which takes pictures of the brain from different angles.

During the scan you will be asked to lie on a scanner table while the scanner rotates around your head. It is a quick and painless examination.

Sometimes a dye (CT contrast agent) is injected into a vein in your arm to help show the tumour more clearly in the pictures.

MRI scan

An MRI (Magnetic Resonance Imaging) scan produces pictures of the head and brain using strong magnetic fields and radio waves. It differs from a standard X-ray as it produces very detailed pictures.

During the scan, you will lie in a long tube. The scan is painless but, unfortunately, the scanner is very noisy. Earplugs or headphones are provided.

If you think you will feel anxious or uncomfortable in the confined space of the scanner tunnel you should tell the staff before the scan. You should also tell them if you unexpectedly feel anxious just before you are due to enter the scanner tunnel.

Sometimes a dye (MRI contrast agent) is injected into a vein in your arm to help show the tumour more clearly in the pictures.

It is not unusual for someone to have an MRI scan after an initial CT scan.

(You might be interested in reading our fact sheet on brain and spine scans for further information.)

Other scans

A small number of people might also have a different type of scan called a PET scan following their CT or MRI scans. PET (Positron Emission Tomography) scans produce detailed three-dimensional colour images of the brain. However, these scans are only available in a small number of hospitals so they might not be available in your area. Also, you will only have this type of scan if your consultant requests one for you.

EEG

Occasionally, if your first symptom was a seizure, you will have an EEG (electroencephalogram). An EEG involves having wires attached to your head for 20 to 30 minutes during which time a recording of the electrical activity in your brain is made. The wires are connected to small pads that are gently attached to your scalp. A skin-friendly glue might be used.

Results of the tests and investigations

The results of these tests will confirm whether your symptoms are caused by a physical problem in your head and will give your medical team some idea whether that problem is a tumour.

If your medical team are able to identify the problem as being a tumour, they might also have some idea whether it is benign or malignant. However, these initial test results alone are unlikely to reveal any definite information about the type of tumour you might have.

Further tests and investigations

Once your doctors have established from your scan or scans that you have a tumour, they might need to obtain a sample of it to be examined by a pathologist (a doctor who specialises in the causes, effects and behaviour of diseases). This procedure is called a biopsy (see below). The pathologist will identify what type of tumour it is and whether it is benign or malignant.

You might also have further brain scans to help the surgeon plan any surgery.

In some cases, your doctors might advise a “watch and wait” policy at this stage. This involves monitoring the tumour closely with further scans to check for any changes in the tumour’s size or behaviour.

Angiogram

An angiogram is an X-ray test used to produce pictures of blood vessels. Occasionally, people will have an angiogram to show the blood supplies of a suspected brain tumour.

After you have had a local anaesthetic, a very small, flexible tube (catheter) is inserted into the blood vessel in your groin (the femoral artery). This is passed through other blood vessels in your body until it reaches the arteries in your neck. While this happens, you will receive injections of a special dye (called contrast agent) to produce more detailed pictures.

You have to be admitted to hospital to have an angiogram and you will need to stay overnight.

(You might be interested in reading our fact sheet on angiogram for further information.)

Biopsy

A biopsy is an operation to remove a small sample of a tumour to be sent for examination by a pathologist (a doctor who specialises in the causes, effects and behaviour of diseases). A preliminary diagnosis is often made during the surgery but it might not be confirmed for several days.

Usually the procedure is carried out through a burr hole (an opening about the size of a small coin drilled into the skull). A needle is passed through the burr hole and into the tumour. A sample of the tumour is taken via the needle.

Often the needle is guided to the tumour with the use of scanning equipment and a special frame that is attached to the head. This is called a stereotactic biopsy. You will be fitted for the frame before the biopsy. Recent advances now allow the procedure to be done without the frame in some cases. This is known as frameless stereotaxis or image-guided surgery.

Biopsies are usually carried out under a general anaesthetic but are sometimes done under a local anaesthetic.

The aim of a biopsy is to help with diagnosis rather than provide treatment. However, in some cases, a larger piece of the tumour can be removed and the biopsy can form part of someone’s treatment.

As with any form of surgery, there are risks associated with biopsies. There is a risk that your symptoms might worsen after the biopsy or that it might cause seizures. Your neurosurgeon will discuss the risks with you before the operation. The risks associated with biopsies are generally small.