TSPO and Stroke: Recently published work has shown that both F-18 labelled tracers have an improved SNR over (R)-[11C]PK11195 in models of acute inflammation [17, 22, 23, 28], but to date, there is neither reported investigation comparing these new tracers nor looking at their performance in a model producing a lower level inflammation (∼2-fold increase in TSPO PET signal), which is more similar to the levels observed in neurodegenerative diseases than stroke [17, 23], excitotoxic lesions [16, 48] or high doses of LPS [28, 34] (∼4–6-fold increase in TSPO PET signal).