How are brain tumors diagnosed?
In many cases, brain tumors are diagnosed in the hospital after the patient has a seizure or other sudden symptoms. Others are diagnosed after seeing their GP because of symptoms. If your GP suspects a brain tumor, they will refer you to a specialist.
The specialist will ask you about your overall state of health, previous medical problems, and your family history. They may perform a physical exam to check your abdomen and chest and also perform a detailed examination of your nervous system (neurological exam):
- Simple questions to check on your thinking, reasoning, and memory.
- Take a few steps or perform repeated movements to check your balance and coordination.
- Check the strength you have in your arms and legs but pushing against something.
- Check your reflexes by tapping your arms and legs.
- Check to see if you feel pinching on your skin and can distinguish heat from cold.
- Check if you have any hearing problems.
You will also have another type of tests such as:
- Blood test and chest x-ray
You will have tests done to check on your overall state of heath; a test cannot diagnose a brain tumor. You may also have chest x-rays done to see how your lungs are functioning.
- MRI (magnetic resonance imaging)
This test uses magnetism to build a detailed image of one of the areas of your body. The scanner is a powerful magnet, which is why you will be asked to fill out and sign a checklist and provide your consent. As part of this consent form, you will be asked if you have any implants such as a pacemaker or surgical clips. You should also tell your doctor if you have ever worked with metals or in the metal industry.
Before the scan, you will be asked to remove all metal belongings, including jewelery. Sometimes, a contrast dye is given by injection in a vein of the arm to help the images come through more clearly.
You will have to remain very still during the test, which lasts about 30 minutes. The process is painless but can be somewhat uncomfortable, and some people experience a bit of claustrophobia. It is also quite loud, though you will be given earplugs or headphones.
- CT (computed tomography)
A CT takes a series of x-rays, creating a 3-D image of the inside of the body. It takes from 10 to 30 minutes and is painless. A small amount of radiation is used, though it is very unlikely to cause you any harm. You will be asked to refrain from eating and drinking for at least an hour before the procedure.
You may be given a drink or an injection with a dye, which makes it possible to see certain areas more clearly. This may make you feel hot for a few minutes. It is important that you inform your health professionals if you are allergic to iodine or have asthma, as you may have a reaction to the injection.
A CT scan can also be given to help guide a biopsy, which involves taking tissue to be examined under a microscope.
It may be necessary to take a small piece of the tumor to examine it and see exactly what kind of tumor it is.
Positron emission tomography (PET) uses low doses of radiation to measure cell activity in different parts of the body. This test offers more detailed information on the part of the body being scanned.
You will not be able to eat for six hours before the test. A slightly radioactive substance is injected into a vein (normally the arm). This is followed by a wait of at least an hour before the examination, which takes between 30 and 90 minutes.
Single-photon emission computerized tomography is a test that is similar to a PET scan, though SPECT makes it possible to see blood flow within the brain.