Arteriography is a technique for producing images of arteries in the body. The resulting image is called an arteriogram. An angiogram is a set of images of blood vessels whether they are arteries or veins. Traditionally these were done by injecting a contrast medium ie a chemical compound which will show up on the Xray image to outline the relevant structure.
When angiography can be used
Angiography can be used in a wide range of situations. Common examples include:
- Patients with peripheral arterial disease with severe intermittent claudication, rest pain, ulcers and gangrene in whom surgery or balloon angioplasty is contemplated. Here the arteriogram acts as a road map for the surgeon or radiologist
- Patients with recurrent strokes in whom carotid artery occlusion is suspected as the cause.
- Patient with a history of severe angina or myocardial infarction who may be suitable for coronary angioplasty or coronary artery by pass grafting
- patients with brain tumours or vascular malformations where surgery may impair the blood supply to healthy tissues.
Many other types of angiography exist including head and neck, ocular, lung, liver and gastrointestinal angiography. Increasingly less interventional angiographic techniques are being devised for example digital substraction angiography where computerised manipulation of the images allows use of less contrast material which can be injected intravenously rather than intraarterially.
Alternative imaging modalities to minimize radiation exposure such as MRI are being used. Completely non invasive techniques are being explored particularly in the coronary circulation such electron beam tomography or angiography.
Traditional techniques involve injection of contrast media into an artery supplying the affected area or organ and then taking an Xray of the relevant part. The injections can be quite uncomfortable. Newer techniques inject contrast into a large vein usually in the arm as if for taking blood and use digital or MRI imaging techniques.
Observation of the patient in hospital for some hours with local pressure application to the site of injection to prevent vessel swelling at the site of injection and rule out significant side effects is the norm.
These depend mainly on the site of injection and include pain on injection, warmth along the track of the vessels , damage to the vessel wall, dissemination of atherosclerotic plaque from the vessel wall and this embolus may become lodged in the lungs,heart brain or distal limb vessels impairing the blood supply to these organs with potentially very serious consequences.
Reactions to the injected contrast medium if they occur are usually mild but may occasionally become serious and include kidney failure and potentially fatal allergic reactions (anaphylactic shock). The risk of serious side effects is between 0.05% for arteriography for peripheral vascular disease and 2% for coronary (heart) angiography, the latter and cerebral angiography being associated with the greatest risk.
Invasive angiographic techniques are usually the most accurate way of diagnosing abnormalities within blood vessels and are usually regarded as the gold standard. Less invasive or non invasive techniques are compared with the former with quoted sensitivity and specificity rates ( measures of accuracy lying between 55- 98%.
Interpretation by an expert in the particular area of interest is mandatory and for most angiograms this is usually a radiologist with a special interest in this area
Last Editorial Review: 21/2/2010