The prevalence of abnormal findings in screening CT brains performed on patients admitted with psychiatric symptoms

Abstract

Background: No clear guidelines exist regarding the role of computerised tomography (CT) as a screening neuroimaging tool in psychiatric practice. The aim of this study was to evaluate the usefulness of historical and clinical parameters on the CT request form, identify the spectrum of CT findings and correlate these to develop guidelines for the use of screening CT brains in patients who present with psychiatric symptoms.Methods: Requests and reports for the brain CT’s of 507 consecutive patients over a 2-year period, between 2013 and 2014, referred from a psychiatric institute for screening CT brain scans, were reviewed. Analysis was performed for the history of trauma and seizures, Glasgow Coma Scale (GCS) score, focal neurological signs, papilloedema, electroencephalograph, relevant blood results and abnormal CT findings. All reports were approved by a consultant radiologist.Results: No abnormality was noted in 69% of CT scans. Cerebral atrophy, infarcts, cysts and calcific foci were present in 30% of patients. One patient presenting with focal neurology had a CT demonstrating an extradural haematoma which required neurosurgical intervention. No focal brain lesions, potentially responsible for the psychosis, were identified in any other patient.Conclusion: Routine CT screening of patients who present with psychotic symptoms, in the absence of focal neurological deficit, does not add value to patient outcome, but rather contributes to the escalating health care expenses and unnecessary radiation dose. CT screening of psychiatric patients should be reserved for patients with reliable predictors of intracranial abnormalities such as lateralising signs, seizures, persistent or worsening headaches; decrease in GCS, papilloedema and in patients where the onset of symptoms occurred at an age above 50.