We used positron emission tomography and magnetic resonance imaging to evaluate 16 patients with transient ischemic attacks or minor strokes and unilateral internal carotid occlusive disease, five with stenosis, and 11 with occlusion. Cerebral blood flow, cerebral metabolic rate of oxygen, oxygen extraction fraction, cerebral blood volume, and T2-weighted magnetic resonance images obtained at 1.5-T were analyzed. Irrespective of vascular disease, patients with a confluent high-intensity area in the middle centrum semiovale had substantially decreased cerebral blood flow and ratio of cerebral blood flow to blood volume in the middle cerebral artery distribution of the cortex, with a substantially increased oxygen extraction fraction. We concluded that the confluent high-intensity area in the deep white matter region indicates hemodynamic compromise in the affected hemisphere in internal carotid artery occlusive disease.