Diagnosis

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

• 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 metastases. A dye may be 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.

  Other imaging tests may include computerized tomography (CT) and positron emission tomography (PET). For example, if the primary tumor causing your brain metastases is unknown, you might have a chest CT scan to look for lung cancer.

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

  The biopsy sample is then viewed under a microscope to determine if it is cancerous (malignant) or noncancerous (benign) and whether the cells are metastatic cancer or from a primary tumor. This information is critical to establish a diagnosis and a prognosis and to guide treatment.