Digital subtraction angiography (DSA): a neurosurgical perspective.

The purpose of this article is to review the contribution of DSA to neurosurgical practice and to outline its advantages and limitations compared to conventional film-screen angiography. DSA is a technique whereby electronic subtraction allows the near instantaneous demonstration of vascular anatomy essentially free of bony detail. Because DSA possesses a high degree of contrast sensitivity, arterial images can be produced after an intravenous injection of contrast medium as well as by selective arterial catheterisation.