How does cerebral angiography work?
Normally, soft, hollow structures such as blood vessels are difficult to see on X-ray images. In a cerebral angiogram a contrast agent (a dye) is inserted into the blood vessels supplying the brain. This helps to produce useful pictures. Contrast is a type of dye that blocks X-rays. By blocking the X-rays, contrast dye makes the structures being examined stand out against the background of the X-ray. This helps doctors to see the shape of the vessels and their structure. Cerebral angiography also uses a special kind of X-ray technique called fluoroscopy. A fluoroscope is an X-ray unit attached to a television screen. The fluoroscope uses a continuous X-ray beam to make a sequence of images. These images are fed to a television-like monitor to create a moving picture. This allows your doctor to watch as the contrast agent fills the blood vessels supplying the brain and to observe any problems or defects.
