Neuroradiological tests using computer-assisted brain scans can help doctors visualize damage to the brain. These tests can include:
The most common imaging test is computerized axial tomography, called a CT or CAT scan. This scan produces an x-ray that shows a cross-sectional image of the brain. CT scans can detect physical changes in the brain such as hematomas and swelling, which may require immediate treatment.
Another useful diagnostic test is magnetic resonance imaging, or MRI, which uses a large magnet and radio waves to generate computerized images of the brain without exposing the patient to x-ray radiation. MRIs produce high-resolution images of brain structures and are painless.
Depending on individual circumstances, a variety of other diagnostic tools and techniques may be employed. These include the following:
An angiogram is a test used to examine blood vessels in the brain. It involves injecting dye into an artery that supplies blood to the brain, usually through a catheter inserted in the groin. The dye outlines the blood vessels, enhancing the view on the x-ray.
An ICP monitor is a device used to measure intracranial pressure, or pressure within the brain. It consists of a small tube, placed into or on top of the brain through a small hole in the skull, connected to a transducer that registers the pressure.
An EEG, or electroencephalograph, is a test to measure electrical activity in the brain. It uses electrodes, in the form of patches, applied to the head.
X-rays, MRIs, and CT scans can detect fractures, hemorrhages, swelling, and certain kinds of tissue damage, but they do not always detect traumatic brain injury. This is because TBI, especially in its milder forms, often involves subtle traumas to the brain that cause chemical and physical changes to brain tissues. These changes often cannot be found with standard imaging procedures. More sophisticated imaging techniques that measure brain cell metabolism, such as single-photon emission computed tomography, called SPECT, positron emission tomography, called PET, or diffusion tensor imaging, called DTI, can help diagnose these milder injuries, but rarely change the treatment plan.
Single-photon emission computed tomography, or SPECT, is a procedure in which a gamma camera rotates around the patient and takes pictures from many angles, which a computer then uses to form a cross-sectional image.
Positron emission tomography, or PET, is a specialized imaging technique that uses short-lived radioactive substances to produce three-dimensional colored images. PET scanning provides information about the body's chemistry not available through other procedures. Unlike other imaging techniques that look at anatomy or body form, PET studies metabolic activity or body function of substances functioning within the body.
Diffusion tensor imaging, or DTI, is a specialized type of MRI that measures the movement of fluid in the brain, detecting areas where the normal flow of fluid is disrupted.