Angiography is a type of X-ray used to examine blood vessels. The images created during an angiography are called angiograms.

Blood vessels don't show up clearly on ordinary X-rays, so a special dye is injected into the area being examined. The dye highlights the blood vessels as it moves through them. The medical name for this type of angiography is catheterisation.

Less commonly, angiographies can also be carried out non-invasively using computerised tomography (CT) and magnetic resonance imaging (MRI). However, the technique used will depend on a number of factors.

Why angiograms are used

The heart is one of the most common areas of the body that needs to be checked using angiography. During coronary angiography, the flow of blood to the heart muscle can be assessed. The procedure can also be used to help diagnose coronary heart disease.

Other conditions that affect blood vessels and the flow of blood through them can also be detected using angiography – for example, aneurysm (where a section of a blood vessel wall bulges due to a weakness in the wall).

Serious arterial disease in the body can cause problems such as strokes, heart attacks, gangrene and organ failure, so for certain people it's important that circulation problems are investigated.

The images from coronary angiography can be used to help plan treatment for angina and heart attacks. Treatment options include medication or surgery, such as a coronary angioplasty or a coronary artery bypass graft.

Other areas of the body that can be examined using angiography include the:

• brain (cerebral angiography)
• lungs (pulmonary angiography)
• kidneys (renal angiography)
• arms or legs (extremity angiography)

Read more about what angiography is used for. 

The angiography procedure

Angiography is carried out in hospital. It takes between 30 minutes and two hours, depending on the complexity of the investigation. You'll usually be allowed to go home on the same day, although in some cases you may need to stay in hospital overnight.

Most angiographies are planned procedures carried out under local anaesthetic, sometimes with sedation. However, general anaesthetic may be used for young children or if the procedure is particularly complex.

A very thin flexible tube called a catheter is inserted into one of your arteries through a small cut. The artery is usually in your groin or wrist. A radiologist (a doctor who specialises in imaging studies) or cardiologist (heart specialist) will guide the catheter into the area that needs to be examined. The dye, known as a contrast dye or contrast medium, will be injected through the catheter and into the blood vessel. A series of X-ray images will be taken.

Read more about what happens during an angiography.

Safety

Generally, angiography is a safe and painless procedure and the risk of serious complications is low.

There can sometimes be minor bruising where the catheter is inserted. Some people may occasionally have an allergic reaction to the contrast dye, although this can usually be easily treated with medication.

Read more about the complications of an angiography.