G.B. Bradac – författare

In this age when we are witnessing a veritable explosion in new modalities in diagnos­ tic imaging we continue to have a great need for detailed studies of the vascularity of the brain in patients who have all types of cerebral vascular disease. Much of the understanding of cerebral vascular occlusive lesions which we developed in the last two decades was based on our ability to demonstrate the vessels that were affected. Much experimental work in animals had been done where major cerebral vessels were obstructed and the effects of these obstructions on the brain observed pathologically. However, it was not until cerebral angiography could be performed with the detail that became possible in the decades of the ''60 ''s and subsequently that we could begin to understand the relationship of the obstructed vessels observed angiographically to the clinical findings. In addition, much physiologic information was obtained. For instance, the concept ofluxury perfusion which is used to describe non-nutritional flow through the tissues was observed first angiographically although the term was not used until LASSEN described it as a pathophysiological phenomenon observed during cerebral blood flow studies with radioactive isotopes. The concept of embolic occlusions of the cerebral vessels as against thrombosis was clarified and the relative frequency of thrombosis versus embolism was better understood. The concept of collateral circulation of the brain through so-called meningeal end-to­ end arterial anastomoses was vastly better understood when serial angiography in obstructive cerebral vascular disease was carried out with increasing frequency.

In this age when we are witnessing a veritable explosion in new modalities in diagnos­ tic imaging we continue to have a great need for detailed studies of the vascularity of the brain in patients who have all types of cerebral vascular disease. Much of the understanding of cerebral vascular occlusive lesions which we developed in the last two decades was based on our ability to demonstrate the vessels that were affected. Much experimental work in animals had been done where major cerebral vessels were obstructed and the effects of these obstructions on the brain observed pathologically. However, it was not until cerebral angiography could be performed with the detail that became possible in the decades of the '60 's and subsequently that we could begin to understand the relationship of the obstructed vessels observed angiographically to the clinical findings. In addition, much physiologic information was obtained. For instance, the concept ofluxury perfusion which is used to describe non-nutritional flow through the tissues was observed first angiographically although the term was not used until LASSEN described it as a pathophysiological phenomenon observed during cerebral blood flow studies with radioactive isotopes. The concept of embolic occlusions of the cerebral vessels as against thrombosis was clarified and the relative frequency of thrombosis versus embolism was better understood. The concept of collateral circulation of the brain through so-called meningeal end-to­ end arterial anastomoses was vastly better understood when serial angiography in obstructive cerebral vascular disease was carried out with increasing frequency.

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.

The current book represents a distillation of the experience gained in diagnosis of intracranial tumors with computed X-ray tomography at the University Hos­ pitals of Berlin, Mainz, and Miinchen. To what purpose? Standard radiological techniques such as pneumoencephalography with lumbar puncture and cerebral arteriography with puncture of the common carotid artery are invasive proce­ dures which entail a certain amount of risk as well as discomfort for the patient. Furthermore, diagnoses made with these procedures rely primarily on indirect signs of an intracranial space-occupying lesion - such as displacement of the air-filled ventricles or of normal cerebral vessels. Only a few types of tumor are demonstrated directly with these techniques. In contrast, computed tomography demonstrates the pathology directly in almost all cases, and this with a minimum of risk and discomfort. In addition, normal intracranial structures are demonstrated, so that the tumor''s effect on its surroundings can be evaluated. Today, almost a decade after HOUNSFIELD''S revolutionary invention, diagno­ sis of brain tumors without computed tomography is almost unthinkable, if not in fact irresponsible.

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.