CT Angiography

ct angiography

Computerized tomographic angiography, also called CT angiography or CTA, is a test that combines the technology of a conventional CT scan with that of traditional angiography to create detailed images of the blood vessels in the body.

In a CT scan, x-rays and computers create images that show cross-sections, or slices, of your body. Angiography involves the injection of contrast dye into a large blood vessel, usually in your leg, to help visualize the blood vessels and the blood flow within them. When the contrast dye is used to visualize your veins, the study is called a venogram, and when it is used to visualize your arteries, it is known as an arteriogram. CT angiography is similar to a CT scan, but the contrast dye is injected into one of your veins shortly before the x-ray image is performed. Because the dye is injected into a vein rather than into an artery, as in traditional angiography, CT angiography could be considered less invasive.

During the study, you will lie down on a table, which passes through a donut-shaped device. Inside the device, a machine takes x-rays in arcs around the area of your body being examined. Tissues of varying densities absorb these x-rays in varying amounts. The computer assigns these densities different numerical values and then plots an image based on these values, in shades of gray. During the CT angiogram, a dose of contrast dye will be injected into one of your veins. As the dye flows through your circulatory system, it will highlight your blood vessels on the scan. A computer will produce 3-dimensional (3D) images of your blood vessels from the x-ray images.