Indications for computed tomographic brain scanning in psychiatric inpatients.

This study examined the rate of use of computed tomographic (CT) scanning as well as clinical parameters pertaining to that used in psychiatric patients. These patients were compared with a randomly selected control group of psychiatric patients who were not scanned. In addition, scan abnormalities were examined and correlated with clinical and electro-encephalographic (EEG) data. CT scanning was used on 13.5% of admissions. On axis 1 of the DSM III-R, the CT scan group had a significantly higher incidence of delirium and dementia (P < 0.05) and a much higher rate of medical illness (P < 0.01) on axis 3. The rate of CT abnormality was fairly high at 45.2%. An abnormal CT scan was associated with the diagnosis of dementia, the presence of organic mental status abnormality and of abnormality on neurological examination. Focally abnormal CT scans were associated with focally abnormal EEGs in a significant number of patients (P < 0.05).