A stroke is a medical condition in which part of the brain receives an insufficient supply of oxygen as the result of an obstruction or loss of blood. Some stokes can have serious complications, while minor strokes may not produce any obvious symptoms. Strokes are diagnosed and evaluated using a combination of physical evaluation and clinical testing. A computer tomography examination (CT scan) often is used to determine the location and severity of the stroke. Using a CT scan for strokes is useful, because it quickly can give doctors an accurate picture of what is occurring within the brain, but the procedure can be expensive and exposes patients to health risks from the radiation and contrast dye.
Time is extremely important for patients suffering from a serious stroke. As the areas of the brain affected by the stroke are deprived of blood, the cells begin to die off from lack of oxygen. More and more brain cells will be permanently damaged as time passes, eventually leading to long-term neurological issues.
Many emergency rooms use a CT scan for strokes, because it can help them determine how best to treat the patient within a short time frame. In some cases, patients are given clot-busting drugs to break up the blockage and restore normal blood flow. Other patients may require surgical procedures to repair damage or relieve swelling within the brain.
The diagnostic use of a CT scan for strokes does have some drawbacks. A CT scan generally is not as sensitive as a magnetic resonance imaging (MRI) and may have difficulty detecting smaller strokes. The CT scan operates on the same principles as X-ray imaging, so this procedure also will expose patients to radiation. This can be a particular concern for children or patients who already have received radiation exposure from other recent diagnostic testing. The dye used to provide contrast in some CT scans can cause an allergic reaction in some patients, although a CT scan for strokes often is performed without contrast agents because of the time it takes to inject the dye into the patient.
Overall, using a CT scan for strokes, as of 2011, provides one of the quickest ways for doctors to diagnose and assess a patient. While there are health risks associated with CT use, including radiation overdose, the ability of medical professionals to quickly determine the location and extent of damage allows them to provide prompt treatment, which can help preserve brain tissue and neurological functioning. In cases in which a CT scan is insufficient, an MRI or other imaging technique may be used to provide doctors with a better picture of what is occurring within the patient's brain.