Review Article

PET and SPECT Imaging of ALS: An Educational Review

Table 4

Summary of chemical structure of neuronal density imaging PET probes along areas of application for ALS research.

PET radiotracerChemical name and structureApplication in ALSReferences

[11C]flumazenilEthyl 8-fluoro-5-(methyl-11C)-6-oxo-5,6-dihydro-4H-benzo[f]imidazo[1,5-a][1,4]diazepine-3-carboxylate
Decreased binding in mainly motor and frontal regions as compared to controls.[6, 65, 66]

[11C]WAY100635N-(2-(4-(2-(methoxy-11C)phenyl)piperazin-1-yl)ethyl)-N-(pyridin-2-yl)cyclohexanecarboxamide
Decreased binding in several gyri and frontotemporal regions through SPM and VOI analysis as compared to controls.[67]

[18F]FPEB3-(Fluoro-18F)-5-(pyridin-2-ylethynyl)benzonitrile
Increased binding in the hippocampus, striatum, and frontal cortex of mice models.[49]

[18F]PSS232(E)-3-(pyridin-2-ylethynyl)cyclohex-2-en-1-one O-(3-(2-(fluoro-18F)ethoxy)propyl) oxime
Increased binding in the striatum, hippocampus, and cortex in mice models and increased binding in the basal ganglia and frontal, motor, and temporal cortices of ALS postmortem tissue.[48]

[18F]fallyprideN-((1-allylpyrrolidin-2-yl)methyl)-5-(3-(fluoro-18F)propyl)-2,3-dimethoxybenzamide
Reduced uptake in the superior frontal gyrus, nucleus accumbens, left temporal lobe, and angular gyrus in patients compared to controls.[68]

[18F]SynVesT-1(R)-4-(3-(fluoro-18F)phenyl)-1-((3-methylpyridin-4-yl)methyl)pyrrolidin-2-one
Decreased binding in the frontal lobe, anterior cingulate, hippocampus-insula region, and right temporal lobe in patients compared with controls.[69]

[18F]OF-NB13-(4-(2-(Fluoro-18F)phenyl)butyl)-2,3,4,5-tetrahydro-1H-benzo[d]azepine-1,7-diol
Decreased binding in postmortem frontal and motor cortex brain tissue compared to control tissue.[70]