Limits of digital substraction angiography to study intracranial aneurysms are due to problems of vessels superposition and complexe anatomy.The 3D rotational angiography with a rotational acquisition of 180° at 30°/sec. allows us to obtain one hundred images which after computarized work-up build up a 3D image.The target volume on the lesion eliminates all superposition. The complexe morphologies are well studied because we can move the target volume at all angles. The resolution is in the order of one hundred of microns.This diagnostic tool is presently the most precise method to perform an angiographic study which allows us to choose the best technic of treatment.In more than 50% of the cases, the endovascular treatment will be indicated by embolization with platinium coils. The 3D rotational angiography will be also of great application to post-treatment evaluation.This new technic of imaging offers a high level of security and a treatment of high quality.