Angiography is a procedure in which blood vessels (arteries or veins) are injected with a dye that shows up on X-ray. The procedure may be only for diagnostic purposes at which time only X-ray images of the blood vessels are obtained; or the procedure may include treatment. The former procedure is called 'diagnostic angiography' and the later 'interventional angiography'. When an artery is injected, it is called arteriography and venography when a vein is injected. Most commonly the arteries are investigated and only occasionally the veins.

Anatomy

• When dye is injected into an artery, it first outlines the arteries then passes through the capillaries and into the veins. There are six regions in the body that are frequently subjected to arteriography:
  
• Cerebral arteriography involves the study of the arteries that go to the brain (Figure 1) The arteries are visualized from their origin in the aorta (the large artery that comes off the heart) to their entire course in and outside the skull

Figure 1 - Arterial anatomy from the aorta to the arteries of the head. © P. Montelone