Beam attenuation devices for digital subtraction angiography.

A set of three contoured and beveled aluminum filters was constructed for routine use in a variety of digital subtraction angiography (DSA) applications. These adjustable devices are designed to compensate for the uneven x-ray penetration that occurs in many radiographic fields and may otherwise lead to video camera saturation, a major source of artifact in DSA. We have used this simple yet versatile adjunct in more than 200 DSA examinations with uniformly satisfactory results. Major advantages include elimination of the procedural delays that may be associated with more conventional approaches (such as the use of a bolus technique) and avoidance of misregistration artifact when pixel-shifting is used.