[Angiographic patterns erroneously suggesting aneurysm of the anterior part of circulus arteriosus]

In the light of a material including 600 cerebral angiographies the authors analyse the incidence of diagnostic difficulties in cases of pseudoaneurysms of the brain resulting from superposition of vascular loops and kinks in the anterior portion of the circulus arteriosus. Methods of prevention of diagnostic errors by additional head positions during angiography are discussed.