Increase in [18F]-Fluoroacetate Uptake in Patients With Chronic Hemodynamic Cerebral Ischemia
Background and Purpose—[18F]-fluoroacetate (18F-FACE) can be used for evaluating glial cell metabolism. Experimental studies have shown an increase in 18F-FACE uptake in rodent models of cerebral ischemia. The aim of this study was to determine whether 18F-FACE uptake is increased in the noninfarcted cerebral cortex in patients with hemodynamic ischemia owing to atherosclerotic internal carotid artery or middle cerebral artery disease.
Methods—We evaluated 9 symptomatic patients with unilateral atherosclerotic internal carotid artery or middle cerebral artery disease and no cortical infarction using positron emission tomography with 18F-FACE and 15O-gases. 18F-FACE uptake during 40 to 60 minutes after injection was compared with the cerebral blood flow, cerebral metabolic rate of oxygen, oxygen extraction fraction, and cerebral blood volume in the middle cerebral artery distributions.
Results—Significant decreases of cerebral blood flow and cerebral metabolic rate of oxygen and increases of oxygen extraction fraction and cerebral blood volume were found in the hemisphere ipsilateral to the arterial lesion, and 18F-FACE uptake in this region was greater than that in the contralateral hemisphere. The relative 18F-FACE uptake (ipsilateral/contralateral ratio) was negatively correlated with cerebral blood flow or cerebral metabolic rate of oxygen values and was positively correlated with oxygen extraction fraction values. Multivariate analysis showed that the ipsilateral/contralateral 18F-FACE uptake ratio was independently correlated with the cerebral blood flow (or oxygen extraction fraction) and cerebral metabolic rate of oxygen values.
Conclusions—In patients with atherosclerotic internal carotid artery or middle cerebral artery disease, 18F-FACE uptake is increased in the noninfarcted cerebral cortex with chronic hemodynamic ischemia characterized by misery perfusion with decreased oxygen metabolism. Increased 18F-FACE uptake may indicate the cortical regions that are at particular risk for ischemic damage.
- Received May 14, 2015.
- Revision received June 15, 2015.
- Accepted July 2, 2015.
- © 2015 American Heart Association, Inc.