Brain Tumors Tests

Brain Tumors Tests

Brain tumors are highly complex, requiring an expert and deeply experienced team that can accurately diagnose your tumor type — so that you get the best and most effective treatment. City of Hope’s team of highly trained experts use their clinical expertise, honed by seeing many different tumor types, to provide you with the most accurate diagnosis.

Diagnosing Brain Tumors

  • A neurologic exam is a test to find out if there are neurological problems, including motor and sensory issues.
  • MRI (magnetic resonance imaging) uses magnets and radio waves to create a series of pictures of the brain and nearby structures.
  • CT (computed tomography) scan uses X-rays to provide detailed images of the brain and spinal structures, revealed as thin cross-sections.
  • PET (positron emission tomography) scan uses a radioactive tracer to locate cancer cells and measure their activity.


A biopsy (a thin sliver of tissue taken from the tumor) may occur after initial imaging and neurologic testing, or it may occur at the earliest stage of diagnosis. That section of tissue is then evaluated based on factors such as:

  • The tumor’s growth potential
  • How the tumor might evolve over time

There are two main ways to perform biopsy for brain cancer, including:

  • Stereotactic biopsy involves guiding a needle to the tumor site in order to extract a small sample of the tumor tissue. Needle biopsy is most often used when the tumor is in an especially risky or sensitive area of the brain.
  • Surgical biopsy is done when imaging reveals a tumor that may benefit from being removed surgically. This type of biopsy usually involves removing a section of the skull — called a craniotomy — and taking out most or all of the tumor.

If it is suspected that cancer has spread through the cerebrospinal fluid, a spinal tap may be performed:

  • Spinal taps are used to test for cancer cells in the cerebrospinal fluid, usually after a brain tumor is already diagnosed. A spinal tap is more commonly used when certain tumor types are suspected to have spread there, such as a lymphomas or ependymomas.