[Neuroradiology and the chiasmatic angle syndrom (author's transl)].

Many diagnostic procedures are available. The main methods are briefly reviewed. Standard X-rays of the skull are always needed. In doubtful cases polytomography is essential. Bone scintigraphy reveals early signs of changes in the bony macrostructures. Brain scintigraphy is still very useful in observing 1. the blood-flow in both intracranial and intraorbital regions, and 2. the cranio-orbital distribution of the radiotracer. Brain scintigraphy is particularly important in detecting meningiomas and vascular lesions. The dynamic study and the comprehensive survey it gives are still not replaced by computer tomography (CT) scanning, which however represents the most powerful advance in this field. The most suitable methods for exploring precise details of vascularisation and structural delineation remain the classical carotid and vertebral angiographies, the orbital and cavernous sinus phlebographies and also the cerebral pneumography. During the last years the accuracy of these methods has greatly increased through technological advance. In many cases they have become indispensable.