The high incidence of cerebral ischemic insults caused by atherosclerotic lesions in the carotid artery warrants a careful diagnostic work-up if the therapeutic possibilities now available are to utilized to the full. Until recently, the diagnosis of carotid stenosis was considered the domain of arterial angiography, but MRI angiography and, in particular, color-coded duplex ultrasonography, have now made these techniques so reliable that-as this case report shows--there is no longer any need for routine angiography for surgical planning. Furthermore, even arteriography involving standard projections may fail to provide the necessary information.