This introduction to digital subtraction angiography (DSA) was presented before the presentations of the panelists. DSA is a new imaging procedure for evaluating cardiovascular disease, images with successful digitization of X-ray picture achieved following the development of CT. DSA is less invasive than ordinary angiocardiography; it features real time imaging, good spatial and temporal resolution, and the capability of providing functional and anatomical information. Although DSA has been applied mainly to the vascular system, its use is being extended to the evaluation of ischemic heart disease. One disadvantage of DSA consists of misregistration artifacts which are caused by temporal subtraction technique. In attempts to overcome this disadvantage, energy subtraction, hybrid subtraction, and the application of a matched filter technique have been investigated. The recent development of angiographic contrast media with low osmolarity will serve to extend the indications for DSA.