Lacunes consist of small vascular lesions with a volume of between 2 and about 30 mm. These lacunar infarctions are determined by an ischemia caused by obstructive diseases of small terminal vessels in the deep areas of the brain. While magnetic resonance currently appears to be a more sensitive diagnostic tool than computed tomography (CT) as far as research into small cerebral lesions is concerned, CT still remains a very valid and more convenient instrument for the screening of these quite frequent pathologies.