• This study attempts to assess the impact of computerized cranial tomography (CT) on clinical practice in a veterans hospital. A CT scan could be performed only if there existed a reasonable potential for the results to affect the patient's clinical course. We document many instances of how the 163 CT scans obtained during a one-year period aided patients. We quantitated one beneficial aspect by estimating the major neuroradiologic contrast procedures obviated by CT scan. Case-by-case review indicates 70 cerebral arteriograms and 58 pneumoencephalograms would have been performed had CT scanning not been available.