Nuclear medicine has established an irreplaceable role in the biomedical research and management of
brain diseases. Its unique capacity to visualize molecular events in vivo as they unfold provides diagnostic
clarity into functional performance and the option for therapeutic intervention. Limitations on access to
brain tissue, however, have traditionally restricted nuclear medicine procedures to use of low molecular
weight radioligands confined to the extracellular space of the brain, e.g., neurotransmitter receptors,
which has precluded the interrogation of many cellular processes likely to be causal in disease etiology.
Developments in radioprobe features and targeted delivery over the past two decades are overcoming
these limitations, expanding the domain within which dysfunctional processes can be examined. These
developments afford the prospect not only of a systemic view of brain diseases but also one likely to be
more proximal to the unfolding dysfunctional events.
