. One hundred and ninety patients underwent a total of 305 repeat brain scans, of which 149 were clinically indicated, whereas 156 were obtained as a "routine" investigation with no deterioration in patients' neurological status. Of the repeated scans, 71 were improved, 169 were unchanged, and 64 were worse. None of the 156 patients who received a "routine" CTB required a change in management. The 149 CTB performed for clinical deterioration resulted in a change in management in 28 patients (19%)