Chronic subdural hematoma: imaging

CT-scan is able to provide the diagnosis of chronic subdural hematoma in mo re than 90 % of the cases. It usually shows a peri-cerebral fluid collectio n along the convexity, with a convex outer border, and an irregular concave inner border. The density of the collection depends on the age of the hema toma. The main difficulties, in tern? of diagnosis, result from bilateral i sodense chronic subdural hematoma, and differential diagnosis between hemat oma, hygroma, and empyema. Some rare localisations can sometimes be seen (p osterior fossa, skull base...). A double density with a sedimentation level , or heterogeneity of the hematoma, can sometimes be seen too. Chronic subd ural hematoma is demonstrated by MRI in almost 100 % of the cases. The inte nsity of the collection, in T1 and T2 sequences, depends on the age of the hematoma.