Traumatic Brain Injury: Nuclear Medicine Neuroimaging

This chapter provides an up-to-date review of nuclear medicine neuroimaging in traumatic brain injury (TBI). Although the role of FDG PET may be limited in the acute phase due to the more rapid availability of CT or MRI, 18F-FDG PET could remain a valuable tool in researching complex mechanisms associated with early metabolic dysfunction in TBI, particularly in the absence of structurally apparent brain damage. 15O2-PET is also a solid technique for research in acute TBI, but in contrast to 18F-FDG PET, it is not widely available due to its high cost. In the chronic TBI phase, most 18F-FDG PET studies converge to identify a diffuse cortical-subcortical hypometabolism involving key regions for cognitive function. In these cases, FDG PET may also be used for the evaluation of therapeutic interventions. More recently, research has focused on the imaging of specific pathological processes, such as neuroinflammation and accumulation of tau, as well as on distinct entities as chronic traumatic encephalopathy and the post-concussion syndrome. In this light, the in vivo demonstration of tau deposits in athletes exposed to repetitive head injury has gained special interest. These techniques may provide useful information, especially in situations where structural damage typically fails to show a pathologic substrate. Despite a paucity of recent research publications, SPECT may still be regarded a valid alternative for the study of TBI.