Central Nervous System: The Brain and Cerebro-Spinal Fluid

Abstract

AbstractNuclear medicine studies of the central nervous system provide unique information on cerebral perfusion and metabolism and the physiology of cerebro-spinal fluid (CSF) fluid. Diagnosis of brain death is based on clinical findings indicating a complete lack of function of the entire brain. Mandatory additional studies supporting the clinical suspicion are required by most countries, such as electroencephalography (EEG), brainstem evoked response audiometry (BERA), transcranial Doppler, and brain scintigraphy. Brain scans following the administration of perfusion agents are considered to represent the most objective assessment tool. FDG PET and possibly ictal-interictal cerebral perfusion SPECT studies are used to identify an epileptogenic focus in drug-resistant epilepsy. The main indication is in patients with likely unifocal seizures at semiology and EEG, and a negative brain MRI, or with MRI findings not corresponding to clinical signs and symptoms and to EEG findings. CSF shunt patency studies involve injection of a radiopharmaceutical into the reservoir of a ventriculo-peritoneal shunt in children with hydrocephalus. The study shows the transit of labelled CSF through the shunt and may detect shunt obstructions. Radionuclide molecular imaging studies on brain tumors are rare and mainly part of research projects and are not performed in routine clinical settings and therefore will not be dealt with in this section.