Value of CT scanning in outpatients: preliminary report on a controlled study.

A series of 100 consecutive new outpatients attending the neuroradiology service for a cranial CT scan between 1 October and 24 December 1984 were analyzed. On the day of the investigation each patient was examined by a neurologist, who gave his opinion on the value of a CT scan. The neurologist's ratings were then compared with the CT reports. More than 2/3 of the requests for CT were useless and could have been avoided by thorough clinical evaluation of the patients and full awareness of what CT scanning can contribute to diagnosis and treatment.