Brain Tumor Diagnosis
Begins with Thorough Neurological Exam
A plethora of considerations or factors are involved in the diagnosis of a brain tumor. Usually, initial symptoms lead to a thorough physical examination. Those initial symptoms include:
- Persistent headaches
- Vomiting or convulsions
- Changes in sight, speech or hearing
- Weakness or loss of sensation of arms, legs, hands or feet
The physical exam, which could be conducted by a neurologist, includes a review of a patient's medical history and neurological tests to assess: balance and coordination, abstract thinking and memory, eye movement, sensory perception, reflexes, control of facial muscles, and head and tongue movements.
Subsequently, based on the examination findings and other factors — age, medical condition, the type of cancer suspected and severity of symptoms — one or more diagnostic tests will be performed. Those tests are accomplished with non-invasive, high-resolution medical imaging applications:
This CT reveals brain abnormalities. Simply, this is a sophisticated X-ray machine linked to a computer to create two-dimensional images. It is painless and can be completed in 10 minutes or less. Occasionally a special dye is injected into the bloodstream to provide more detail.
The MRI, which uses magnetic fields, not X-rays, to provide detailed images, is more sensitive than the CT in detecting a brain tumor's presence. The MRI is a preferential imaging test because it outlines the normal brain structure in unique detail. The test procedure is slightly more time consuming as the patient lies inside a cylinder-type machine for about one hour. A special dye may also be injected in the bloodstream during the procedure (MRI angiogram) to distinguish tumors from healthy tissue.
Other Scans or Diagnostic Tests
Additional scans include magnetic resonance spectroscopy (MRS), single-photon emission computed tomography (SPECT) or positron emission tomography (PET) . These scans assist in determining brain tumor activity and blood flow or the effect on brain activity.
X-rays — might reveal changes in the skull bones, indicating a tumor. Because this is a far less sensitive test than scans, it is used infrequently.
Digital holography — provides three-dimensional map of the tumor and surrounding brain structure.
Myelography — an X-ray of the spine to detect spinal cord tumors.
Radionuclide brain scintigraphy — views capillaries feeding the tumor after highlighting them with a radioactive substance.
Several of the tests can suggest the presence of a tumor, but the biopsy, which is a piece of the tumor, provides the definitive diagnosis. Depending on the tumor, the biopsy also reveals the type and grade of the tumor and assists in potential treatment. The sample tumor is analyzed by a pathologist, a doctor specializing in tissue, cell and organ evaluation to diagnose disease.