Digital subtraction angiography (DSA) is a method for seeing blood vessels following an injection of radio-opaque solubles. Particular care has to be taken when using this technique as the invasiveness and potential toxicity of radiopaquecontrast material. 

 

This test is commonly used to see all arteries, veins and organs in the body with the use of injecting a dye into the inferior vena cava. This method was developed by Cas.tellanos, Robb and Steinberg as a way to isolate vessels unseen in neuroradiology. Beffore computers were used, radiologists simply took x-rays of the ara before using a dye and after using a dye to see the difference. This proved ineffective and unreliable as the dotors were forced to second guess decisions on diagnoses. 

 

First, the patient is set up with an IV. An x-ray is taken before the dye is injected into the IV, and this is called the mask image. After the mask is made, the contrast, gadopentetate dimeglumine, is administered through the IV. 

 

A radiologist then uses equipment such as an image intensifier that continues taking pictures of the images at a regular rate. All the images after the mask image are taken away, so that every vein and artery can be seen. 

 

However, more radiologists and doctors are turning to computed tomography angiography (CTA) that produces 3D images and avoids some of the invasiveness of the procedures currently used.