CT Scanning and Subdural Empyema

To the Editor.— We would like to submit our experience concerning the failure of computed tomographic (CT) scanning to detect subdural empyema in corroboration of the recently reported observations of Ralph O. Dunker, MD, and Rashida Khakoo, MD (1981;246:1116). In their article they described two patients who had subdural empyemas rapidly develop as a consequence of fulminant sinusitis. Although the clinical course in these patients strongly suggested an infectious, space-occupying lesion, CT scans remained nondiagnostic. Our recently reported experience, which studied the intracranial complications of frontal sinusitis, included three subdural empyemas. 1 These cases exhibited a similar progression of neurological signs and symptoms. In all three cases, CT scans failed to disclose the presence of subdural pus. Subsequently, carotid arteriography was performed and in each instance demonstrated a subdural empyema. Interestingly, the epidural abscesses in our study were more readily detected on CT scans. We hope that future experience with