Increase in [18F]-Fluoroacetate Uptake in Patients With Chronic Hemodynamic Cerebral Ischemia

Abstract

Background and Purpose— [18F]-fluoroacetate ( 18 F-FACE) can be used for evaluating glial cell metabolism. Experimental studies have shown an increase in 18 F-FACE uptake in rodent models of cerebral ischemia. The aim of this study was to determine whether 18 F-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 18 F-FACE and 15 O-gases. 18 F-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 18 F-FACE uptake in this region was greater than that in the contralateral hemisphere. The relative 18 F-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 18 F-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, 18 F-FACE uptake is increased in the noninfarcted cerebral cortex with chronic hemodynamic ischemia characterized by misery perfusion with decreased oxygen metabolism. Increased 18 F-FACE uptake may indicate the cortical regions that are at particular risk for ischemic damage.

Hemodynamics and oxygen extraction in chronic large artery steno-occlusive disease: Clinical applications for predicting stroke risk

“…We found no evidence for reduced CMRO 2 in these patients, however. A recent study by Yamauchi et al 96 reported increased 18F-Fluoroacetate uptake, an indicator of glial metabolism in non-infarcted regions with reduced CBF, increased OEF, CBV, and reduced CMRO 2 .…”

Development of 2-(2-(3-(4-([18F]Fluoromethoxy-d2)phenyl)-7-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)ethyl)-4-isopropoxyisoindoline-1,3-dione for Positron-Emission-Tomography Imaging of Phosphodiesterase 10A in the Brain

“…For example, the coefficient of variation (CV) in measurements of the binding potential (BP ND ) of [ 18 F] 5 with the Logan graphical method was higher than 30% in nonhuman-primate brains . Further, it was reported that some PET ligands containing a 2-[ 18 F]­fluoroethoxy group are easily metabolized via the cytochrome-P450 monooxygenase system in the liver, resulting in [ 18 F]­fluoroacetaldehyde. , Subsequently, [ 18 F]­fluoroacetaldehyde is rapidly oxidized to [ 18 F]­fluoroacetate, which is easily accumulated in brain and has even been used as an imaging tool for detection of cerebral ischemia. , Thus, high variation in quantitative PET measurements of [ 18 F] 5 may be caused by contamination with [ 18 F]­fluoroacetate in the brain.…”

“…43,44 Subsequently, [ 18 F]fluoroacetaldehyde is rapidly oxidized to [ 18 F]fluoroacetate, which is easily accumulated in brain and has even been used as an imaging tool for detection of cerebral ischemia. 45,46 Thus, high variation in quantitative PET measurements of [ 18 F]5 may be caused by contamination with [ 18 F]fluoroacetate in the brain.…”