The Diagnosis of Chronic Subdural Hematoma by Computerized Axial Tomography

Abstract

The clinical diagnosis of chronic subdural hematoma and pachymeningiosis hemorrhagica interna is extremely difficult, because neurologic and psychologic symptoms are not typical. This is especially true for patients who have no head injury in their history. One-dimensional echo encephalography was a progress in the diagnosis of chronic subdural hematoma, because it became possible to diagnose a midline shift in almost every unilateral hematoma. In 75–80% of all cases, reflections at the internal membrane of the hematoma, the so-called hematoma echos, may be recorded. Brain scintigraphy is able to prove a chronic subdural hematoma in 84% of all cases. The final diagnosis was hitherto usually made by cerebral angiography. The question of whether axial CT as a new noninvasive method would be able to diagnose chronic subdural hematoma was of great interest. The first observations made by AMBROSE in 1973 were not encouraging, as he could only detect one out of seven subdural hematomas by CT. However, indirect signs of a space-occupying lesion were always present.