Diagnosis

If it's suspected that you have a brain tumor, your doctor may recommend a number of tests and procedures, including:

• A neurological exam. A neurological exam may include, among other things, checking your vision, hearing, balance, coordination, strength and reflexes. Difficulty in one or more areas may provide clues about the part of your brain that could be affected by a brain tumor.

• Imaging tests. Magnetic resonance imaging (MRI) is commonly used to help diagnose brain tumors. Sometimes a dye is injected through a vein in your arm during your MRI study.

  A number of specialized MRI scan components — including functional MRI, perfusion MRI and magnetic resonance spectroscopy — may help your doctor evaluate the tumor and plan treatment.

  Sometimes other imaging tests are recommended in certain situations, including computerized tomography (CT) and positron emission tomography (PET).

• Collecting and testing a sample of abnormal tissue (biopsy). A biopsy can be performed as part of an operation to remove the brain tumor, or a biopsy can be performed using a needle.

  A stereotactic needle biopsy may be done for brain tumors in hard to reach areas or very sensitive areas within your brain that might be damaged by a more extensive operation. Your neurosurgeon drills a small hole into your skull. A thin needle is then inserted through the hole. Tissue is removed using the needle, which is frequently guided by CT or MRI scanning.

  The biopsy sample is then viewed under a microscope to determine if it's cancerous or benign. Sophisticated laboratory tests can give your doctor clues about your prognosis and your treatment options. Studying your biopsy sample and determining exactly which type of brain tumor you have is a complex process. If you're uncertain about your diagnosis, consider seeking a second opinion at a medical center where many brain biopsies are evaluated every year.