NEUROLOGICAL APPLICATIONS OF SINGLE-PHOTO N EMISSION TOMOGRAPHY

Brain single photon emission tomography is a functional imaging modali ty in constant evolution. Tracers belong to 4 categories; blood pool t racers, perfusion tracers, ligands of receptors, ''metabolic'' tracers . Examination conditions must be accurately described since they may c ause specific cerebral activation. The interpretation must be done in comparison wit a morphological examination (CT or NMR). Cerebrovascula r diseases, temporal lobe epilepsy and dementia were the first domains of application. Now many studies concentrate on cerebral cognitive or pharmacological activation procedure before the tracer injection to c apture an aspect of the brain functioning. It is mandatory to clearly state what is expected form the examination: an answer for a given pat ient and a specific question or a study of an homogenous group of pati ents. In order to yield relevant results, such studies must rely on ri gorous methodology.