[Hemodynamics in the cerebral cortex and basal ganglia--observation on normal volunteers and patients with lacunes using PET].

We examined ten healthy volunteers using positron emission tomography (PET) in order to elucidate regional changes and correlations in the cerebral circulation and oxygen metabolism. We also studied eight lacunar stroke patients so as to disclose the influences of vascular risk factors and aging on the cerebral blood flow and metabolism. We can conclude from our result as follows: 1. Cerebral blood volume (CBV) was minimum in the basal ganglia and cerebral blood flow (CBF)/CBV ratio was higher than that of cerebral cortex in healthy volunteers; 2. CBF of gray matter in healthy volunteers correlated with CBV and cerebral metabolic rate of oxygen where oxygen extraction fraction inversely correlated with CBF, CBV, and CBF/CBV; and 3. the basal ganglia CBF/CBV ratio in lacunar stroke patients was lower than that of healthy volunteers. These findings suggested that the perfusion pressure in the basal ganglia was so high in the normal condition that the angionecrosis or occlusion in the perforating arteries would be induced, especially in the aged and hypertensive patients.