Diagnosis often begins with a medical history. Your doctor will ask about your symptoms, health habits, and past illnesses and treatments. He or she will also do a neurological exam to check your
response to pain
Your doctor may also order one of these imaging tests:
Computed tomography (CT) scan. This test creates cross-sectional images of the brain. It uses an x-ray camera that rotates around the body. A dye sometimes is injected into a vein prior to the scan to make the tumor more visible.
Magnetic resonance imaging (MRI). This test uses a powerful magnet, radio waves, and a computer to create pictures of the brain. An MRI may provide a better view of some parts of the brain than a CT scan. A special dye may be injected into the bloodstream to enhance the images. A magnetic resonance angiogram is similar to an MRI, but it looks at the flow of blood in arteries. This can help doctors find aneurysms or better define tumors.
Positron emission tomography (PET) scan. For this test, radioactive glucose (sugar) is injected into a vein. A rotating scanner highlights areas where cells are consuming lots of glucose. (Cancer cells use more glucose than normal cells.)
If a brain tumor is suspected to be a secondary cancer, imaging tests also may be done of other organs.
Your doctor may also want to do a lumbar puncture (spinal tap). During this test, spinal fluid is taken from the lower back with a needle. The fluid can be checked for signs of infection or cancer cells.
In rare cases, doctors may want to remove a small piece of tumor tissue before diagnosing the cancer. This is called a biopsy.