What is the difference between a ct and a ct angiogram?

Adding contrast: Computerized axial tomography CAT or CT is a form of x-ray imaging without using any dye or contrast. If the radiologist injects a dye or contrast to highlight the blood vessels during the procedure that would be CT angiogram.

Timing. : Both studies are CT scans. Conventional CT , if contrast is used, takes images once the dye has made its way into the soft tissues and organs of the body. CTA takes the images while the dye is still in the arteries. CT can also be done without dye in certain situations. CTA always needs dye to see the vessels. See radiology info.org for more details.