[Utility and validity of SPECT and PET in the perioperative managements of patients with cervical internal carotid artery stenosis].

In this review, the author describes basic but essential knowledge on cerebral blood flow and metabolism in managing the patients with occlusive carotid artery diseases. Oxygen extraction fraction (OEF) and cerebrovascular reactivity to acetazolamide have widely been accepted as valuable parameters to identify the critical reduction of cerebral perfusion pressure in these patients. These parameters would play an important role in determining the candidates for extracranial-intracranial arterial bypass and in predicting their outcome. However, pathophysiology of cerebral ischemia in occlusive carotid artery diseases is not fully understood yet, and further studies would be warranted. Next, the author reviews previous reports on cerebral hemodynamics and metabolism in patients with severe stenosis of cervical internal carotid artery. Carotid endarterectomy (CEA) and carotid artery stenting (CAS) can dramatically improve cerebral hemodynamics, but may carry the risk to induce silent or symptomatic hyperperfusion in a certain subgroup of patients. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) may also be useful for identifying patients at higher risk for postoperative hyperperfusion.