Table 3.

Situations in which brain imaging is mandatory, with magnetic resonance imaging generally being preferred modality

Symptom or signWhy imaging mandatory
Localising signs on neurological examIdentify focal pathology and/or exclude space-occupying lesion
New-onset seizuresIdentify focal pathology and/or exclude space-occupying lesion
Cognitive impairment excessive and/or atypical for psychiatric condition (and not explained by delirium, intoxication, etc)Assist in identification of potential neurological or degenerative cause
Possible encephalitis (eg pyrexia, headache, seizures, cognitive impairment)Visualise inflammation, assist in exclusion of other potential causes of symptoms
Possible fall, cognitive impairment, vulnerability factors such as anticoagulation or alcoholismExclude subdural haematoma