title: [CT findings in chronic subdural hematomas (author's transl)].
abstract: CT findings of 46 patients with operatively confirmed chronic subdural hematomas are reviewed. The analysis of the EMI scans resulted in three different types of CT findings. Type 1  is characterized by decreased attenuation of the hematoma contents compared to brain tissue. The hematoma is visualized as a lens-shaped low density area between the skull and the surface of the brain. Type 2 apart from low density areas contains zones of increased attenuation due to recent bleeding into a watery chronic subdural hematoma. In many cases sedimentation causes a well-defined horizontal borderline between the thin fluid parts in the anterior portion and the blood debris in the posterior portion of the hematoma sac. Type 3 shows the same average absorption values as normal brain tissue, a direct visualization is not possible. However , the presence of a midline displacement in combination with ventricular compression and absence of a circumscript lesion even after contrast enhancement, allows the diagnosis of a unilateral chronic subdural hematoma in these cases too. Bilateral chronic subdural hematomas may cause considerable diagnostic difficulties if only one or none of the hematomas is visualized. A relatively small midline displacement points to a second bleeding on the opposite side. Most frequent were hematomas of type 1 (37%), type 2 and 3 could be observed in 30,5% resp. 32,5% of cases respectively.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001930:Brain Injuries / Q000150:complications; D002908:Chronic Disease; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006408:Hematoma, Subdural / Q000145:classification / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging / Q000379:methods; D013997:Time Factors; D014054:Tomography / Q000379:methods
vernacular_title: Zur Diagnose des chronischen subduralen Hämatomas im Computer-Tomogramm