How is a brain tumor diagnosed?
The most accurate diagnosis of a brain tumor is made with surgery, which permits the neurosurgeon to see the tumor and obtain a specimen for a pathological examination. Diagnostic surgery is not without its risks, however and there are several diagnostic procedures available today that have considerably improved the chances of detecting brain tumors without resorting to surgery. If a patient’s symptoms lead the doctor to suspect a tumor, then a neurological examination, computerized tomography (CT) scans, and magnetic resonance (MR) imagings are the first diagnostic tools most often used to determine if more definitive procedures are needed. Other studies, such as X-ray films of the head and skull, an electroencephalogram (EEG) or radioisotopic brain scans, may also be done.
A. The doctor does a complete physical exam with special attention to neurological examination. This includes checks for alertness, muscle strength, coordination, reflexes and response to pain. The doctor also examines the eyes for swelling caused by a tumor pressing on the nerve that connects the eye and the brain. The doctor may request a CT (or CAT) scan or an MRI. A CT scan is a series of detailed pictures of the brain. The pictures are created by a computer linked to an X-ray machine. Sometimes dyes are injected into to help show differences in the tissue of the brain. An MRI (magnetic resonance imaging) gives pictures using a powerful magnet linked to a computer. An MRI is helpful in diagnosing brain tumors because it can “see” through the bone of the skull to the tissue underneath. A dye may also be used to enhance the likelihood of detecting the tumor. An MRS (magnetic resonance spectroscopic) is a non-invasive method that can be used with MRI to provide information about cellu
When symptoms arise that may indicate a brain tumor, the first step in diagnosis will involve a basic neurological exam. This kind of exam will measure central nervous system responses, and might include: vision testing, hearing tests, reflex responses, balance and coordination tests, sense of touch tests, sense of smell tests, and various memory and thinking tests. Conventional x-rays do not show tumors growing behind the bones of the skull; so special scans are used to look for tumors. Computerized Tomography (CT) or Magnetic Resonance Imaging (MRI) scans both use computer graphics to create an image of the brain. For both of these scans, the patient lies on a table that slides into the imaging device. For the images to be precise, the patient must lie very still. If the patient is unable to lie still, sedation may be required. Often an injection of a special contrast material is given to help enhance the images. The scan can be very noisy, and the length of time varies. The CT and M
