Intravenous digital subtraction angiography

Intravenous digital subtraction angiography (IV-DSA) is a form of angiography which was first developed in the late 1970s.

IV-DSA uses a computer technique which compares an x-ray image of a region of the body before and after radiopaque iodine based dye has been injected intravenously into the body. Tissues and blood vessels on the first image are digitally subtracted from the second image, leaving a clear picture of the artery which can then be studied independently and in isolation from the rest of the body.

Some studies have indicated that IV-DSA is not suitable for patients with diabetes or renal insufficiency because the dye load is significantly higher than is used in arteriography. However, IV-DSA has been used successfully to study the vessels of the brain and heart and has helped detect carotid artery obstruction and to map patterns of cerebral blood flow. It also helps detect and diagnose lesions in the carotid arteries which is a potential cause of strokes.

IV-DSA has also been useful in assessing patients prior to surgery and after coronary artery bypass surgery and some transplant operations.