Applications of angiography have expanded to include not only diagnostic proce- dures but also therapeutic interventions. The introduction of regional administra- tion of vasoactive drugs through percutaneously placed angiographic catheters was soon followed by methods of transcatheter vessel occlusion using temporary or permanent embolic materials. At the same time methods of opening up nar- rowed or completely obstructed blood vessels with percutaneously introduced balloon catheters were being perfected. Thus, regional blood flow reduction or regional blood flow increase can now be accomplished with percutaneous angiographic methods in lieu of major surgical interventions. The advantages in terms of reduced morbidity, length of hospital stay and cost are evident. Therapeutic angiography is a rapidly advancing and therefore changing field. This monograph aims at capturing some of the most recent advances and also at presenting some of the controversies. In order to accomplish this task the editors invited a selected group of cardiovascular radiologists, to contribute in their respective fields of therapeutic angiography. For a balanced view other experts - usually nonradiologists - were also asked to present their views, com- ments, and criticisms. Whenever opinions were far apart an opportunity was given for reply or rebuttal. Thus, up-to-date information with supporting or oppos- ing expert views is presented on the topics of transluminal angioplasty, transcath- eter vessel occlusion, regional drug infusions, and radiologic interventions in thromboembolic disease.