Diagnosing a brain tumor may occur because you are exhibiting symptoms that warrant investigation, or it may be an incidental finding. For example, if you fall and hit your head, you may come to the emergency department to make sure that you do not have a brain bleed; but when the CT scan of the brain is performed, the radiologist notes the incidental finding of a hypotenuse lesion within the frontal lobe of the brain. In these cases, the finding was incidental, but it is significant and warrants further investigation.
The first step in diagnosing a patient with a brain tumor is to visit a board certified physician who specializes in the Central Nervous System (brain and spinal cord), such as a Neurosurgeon or Neurologist. The physician will perform a physical examination, focusing on the neurological function of the brain. The exam will include testing your cranial nerves, which will involve checking your vision, hearing and smell. It will also involve testing your ability to move your eyes in all planes of direction. Motor muscle strength and sensory evaluation will also be observed to determine if there are any sensory deficits. Finally your reflexes will be checked for balance and coordination. If any of this is abnormal, then the physician may wish to further evaluate you with imaging studies.
The best study to evaluate the brain for a tumor is an MRI. MRI stands for Magnetic Resonance Imaging, which allows for direct visualization of the soft tissues, muscles and brain tissue. There are many different types of MRI studies now that will provide better, more specialized results. Those include: functional MRIs, perfusion MRIs and MR Spectroscopy.
Other imaging studies may be utilized in some instances. These include CT scan of the brain, or if distant metastatic spread is a concern, a PET scan may be indicated. PET stands for Positron Emission Tomography (PET).
If your physician feels that further evaluation is necessary, then surgery or biopsy may be recommended. There are many different types of biopsies and surgeries that it will be best to discuss those with your Neurosurgeon and Oncologist, to determine the most appropriate course for your individual case.