[Nuclear medicine diagnostic in hydrocephalus (author's transl)]

Some of the main questions about hydrocephalus, its origin and classification are reviewed. Routine radioisotope studies of the CSF pathways during 11 years has brought many valuable criteria for defining pathological cases. Attention is focused on the various states of balance between production and resorption of the CSF in hydrocephalus in order to find the right time for placing a shunting device. Radioisotope studies can provide clear images, patterns and criteria. In most instances hydrocephalus may be defined whether compensated or not. They also give a true representation of this unsteady dynamic state which constitute hydrocephalus. Dubious or intermediary cases still exist for which only dubious or intermediary cases still exist for which only dubious results are to be expected. The "pattern recognition" problem is emphasized while technical problems, so important they may be, are only summarized. Radioisotope studies still remain the most valuable and informative test for stuying the third circulation in men. The successive imaging of the various cisterns in different planes must be clinically interpreted, and may be repeated in dubious cases according to the clinical status.