Diagnosis

Tests and procedures used to diagnose astrocytoma include:

• Neurological exam. During a neurological exam, your doctor will ask you about your signs and symptoms. He or she may check your vision, hearing, balance, coordination, strength and reflexes. Problems in one or more of these areas may provide clues about the part of your brain that could be affected by a brain tumor.

• Imaging tests. Imaging tests can help your doctor determine the location and size of your brain tumor. MRI is often used to diagnose brain tumors, and it may be used along with specialized MRI imaging, such as functional MRI, perfusion MRI and magnetic resonance spectroscopy.

  Other imaging tests may include CT and positron emission tomography (PET).

• Removing a sample of tissue for testing (biopsy). A biopsy can be done with a needle before surgery or during surgery to remove your astrocytoma, depending on your particular situation and the location of your tumor. The sample of suspicious tissue is analyzed in a laboratory to determine the types of cells and their level of aggressiveness.

  Specialized tests of the tumor cells can tell your doctor the types of mutations the cells have acquired. This gives your doctor clues about your prognosis and may guide your treatment options.