Although it may seem a rash, even ill-conceived, undertaking to devote a mono­ graph to cerebral angiography at a time when CT seems to be the most important neuroradiologic procedure, this is definitely not the case. Moreover, the authors are aware of the necessity of taking these new techniques into account. Cerebro-arterial occlusive diseases are frequently the cause of acute and chro­ nic neurologic disturbances. The authors' aim in preparing this book was to demonstrate the value of neuroradiology in the diagnosis of these conditions. They have accomplished their purpose, and above all, they have succeeded in demonstrating how angiography and CT complement each other. They point out the absolute necessity of high quality in angiographic imaging; indeed, arterial occlusive diseases may have a very capricious and unexpected evolution that can be followed-up by iterative CT examinations - for instance once a week - but angiography, which is performed only once, must be as perfect and informative as possible. Both authors received part of their training in the Neuroradiologic Depart­ ment of the University Hospital in Strasbourg. I am thus very pleased to find in this book both the perfection I was accustomed to seeing in G. B. BRADAc's iconography and the sound judgement I always appreciated in R. OBERSON. Therefore, it is with great satisfaction that I write this foreword. It is my wish that both authors achieve the recognition they rightfully deserve in the Univer­ sities of Berlin and of Lausanne.