A cerebral angiogram is a medical imaging technique that specifically targets the blood vessels of the brain. This test is used to observe blood flow within the vessels on a detailed scale, allowing physicians to diagnose existing problems or spot risky areas before they become hazardous. Cerebral angiogram requires a special dye, called a contrast medium, to be injected into an artery either in the arm or the leg. This allows pictures to be taken at different times to vividly display the dye's progress as it flows through the observed arteries and veins. Using X-ray based imaging, the doctor can quickly determine if there are any blood clots or narrowed blood vessels, and their location, with startling precision.
Cerebral angiogram may be the first diagnostic imaging technique used, or it may be used to enrich findings from a less-detailed procedure. Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) angiography are more commonly used because they do not require injections to function properly.
The injection may cause an allergic reaction to the dye or persistent bleeding at the injection point, which is an unnecessary risk for most routine check-ups. However, if the patient is displaying symptoms characteristic of an aneurysm, a stroke or similar blood vessel malignancy, the doctor may suggest starting with a cerebral angiogram for the patient's own well-being. This procedure is largely avoided in pregnant patients due to the possibility of the dye passing through the placenta into the bloodstream of the fetus.