Long term effects of the introduction of noninvasive investigations in neuroradiology. Part 1: Overall trends.

A 25 year retrospective survey of requests for imaging studies in a neurological hospital showed that the introduction of radionuclide scanning service had a relatively minor effect on the demand for other investigations. The introduction of computed tomography ten years later had a profound and continuing effect on not only the pattern and volume of requests for imaging, but also on inpatient discharges and outpatient attendances.