An 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, and it appears white on the angiogram. The medical name for this type of angiography is a catheter angiogram.
Less commonly, angiographies can also be carried out using magnetic resonance imaging (MRI) and computerised tomography (CT) techniques.
These pages mainly focus on catheter angiograms.
Why angiograms are used
An angiography can help diagnose conditions that affect blood vessels and the flow of blood through them. These include:
- coronary heart disease – the blood flow through the artery that supplies the heart is disrupted because it has become narrowed
- aneurysm – a section of a blood vessel wall bulges outwards due to a weakness in the wall
- atherosclerosis – blood vessels become clogged up with fatty substances, such as cholesterol; an angiography can be used to assess the level of atherosclerosis in specific blood vessels
The image on an angiogram can also be used to help plan surgery that involves the blood vessels, such as a coronary angioplasty, which is sometimes used to treat coronary heart disease.
Read more about what an angiography is used for.
The angiography procedure
An angiography is carried out in hospital. It takes between 30 minutes and two hours, depending on the complexity of the investigation. You will usually be allowed to go home on the same day, although in some cases you may need to stay in hospital overnight.
In most cases, angiographies are planned procedures that are performed under local anaesthetic. However, general anaesthetic may be used if young children need to have the procedure.
A catheter (a very thin, flexible tube) is inserted through a small cut and into one of your arteries, usually in your groin or your leg. A radiologist (a doctor who specialises in imaging studies) will guide the catheter into the area that needs to be examined. The dye (medically known as a contrast dye or contrast medium) is injected through the catheter and into the blood vessel. A series of X-rays is then taken.
Read more about what happens during an angiography.
Safety
An angiography is a generally safe and painless procedure. The risks of serious complications are low.
Sometimes, an angiography can cause minor bruising where the catheter is inserted. Also, some people may occasionally have an allergic reaction to the contrast dye. This is usually easily treated with medication.
Read more about the complications of an angiography.
