Digital subtraction angiography (DSA) is a fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment.

[3][4] In traditional angiography, images are acquired by exposing an area of interest with time-controlled x-rays while injecting a contrast medium into the blood vessels.

[3] The images are useful for determining anatomical position and variations, but unhelpful for visualizing blood vessels accurately.

Some limited studies have indicated that IV-DSA is not suitable for patients with diabetes or kidney failure because the dye load is significantly higher than that used in arteriography.

[6] 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.