The new FDG brain revolution: the neurovascular unit and the default network.

The first revolution was explosive. Using 18F-fluorodeoxyglucose (FDG), it was possible to see and study the living brain in humans! Pioneers were top experts who provided different specialized expertise, but strictly cooperating between themselves [1]. Physicists, engineers and mathematicians were actively involved in producing the best hardware and software. The research on crystals, in identifying the most effective electronics, in defining accurate methods for attenuation and scatter correction and so on, was nevertheless limited by the relatively poor technology, with the main consideration being limited computer power. These developments stimulated a major interest in the brain. Satisfactory sensitivity and resolution, together with reliable solutions to the technical problems, were only achieved with dedicated cerebral PET scanners which had a field of view that permitted exclusive analysis of the brain. ....