Forty seven cases of central nervous system cavernous angioma (21 males and 26 females) are described. The main clinical signs were epilepsy and brainstem syndromes. Digital subtraction intraarterial angiography, when used, failed to reveal cavernoma. CT detected many of the lesions, but the most successful supplementary diagnostic procedure was MRI which produces highly characteristic images of cavernous angioma. The diagnosis of cavernous angioma was confirmed in the 18 cases in which the tumour was removed surgically. ities." CT and MRI, however, have both proved to be valuable diagnostic aids, the latter especially27 28 (the number of cavernomas diagnosed may be expected to increase rapidly in the near future). CT shows cavernomas as hyperdense or heterogeneous lesions (more rarely as hypodense ones), and a variable degree of enhancement after intravenous contrast injection is quite common, as is calcification.2"'0 Triple-dose injection with delayed detection has b'een used to improve sensitivity."l 32In this article we describe and discuss the clinical, angiographic, CT and MRI signs of 47 patients with CNS cavernomas. Patients and methodsWe studied retrospectively 47 patients in a three year period (December 1986-November 1989

BACKGROUND AND PURPOSE:In 2011, the International Commission on Radiologic Protection established an absorbed-dose threshold to the brain of 0.5 Gy as likely to produce cerebrovascular disease. In this paper, the authors investigated the brain doses delivered to patients during clinical neuroradiology procedures in a university hospital.

The existence of the accessory middle cerebral artery (AMCA) is a rare anatomical variation with an estimated incidence of 0.31%. The embryological development of this artery is unknown. Three anatomical subtypes are described: in the type 1 variety the AMCA arises from the internal carotid artery; in the type 2, the AMCA originates from the proximal part of the anterior cerebral artery; in type 3, the AMCA arises from the distal part of the anterior cerebral artery. The use of endovascular techniques to treat cerebral vascular malformations requires knowledge of the anatomical subtype of AMCA and the brain regions it supplies (cortex, basal ganglia).

Staged preoperative embolization with Onyx followed by microsurgery has made possible 100% cure of complex AVMs with 0% mortality, 15.4% disabling complications and 15.4% non-disabling complications. Complete Onyx resection is not essential to achieve the cure of the patient.