[Pathophysiology of cerebrovascular disorders: PET imaging of the brain]

To understand the underlying mechanisms that occur during cerebral ischaemia and stroke one needs to assess the relationship between blood flow, oxygen and glucose metabolism, and other physiological processes as a function of the site of deficit, the time course of the tissue damage, and the etiology of the ischaemia. PET has already demonstrated its ability to provide in vivo biochemical and pathophysiological information. PET can provide the necessary understanding of the abnormal cellular biochemical processes that occur in response to perfusion insufficiencies in humans. The application of PET to cerebrovascular disease has provided information on temporal course of blood flow and volume, oxygen, and glucose utilization, as well as the respective extraction fractions for these substrates. Additionally, PET provides useful information on neurotransmission, by using receptor ligands one can measure the different receptor systems in the brain.