retrospective analysis of CT manifestations in 63 casos of chronie subdural hematoma was carried out.The duration of hematoma wasnt relatcd to its density
but to its shape。And we thought that (1)Unilateral compression and gathering of the ipsilateral cortical gyri;(2)Gray-whitematter interface displacement;(3) Cortieal line interface displacement;(4) Characterized shift ofmiddle structure were very significant for diagnosis of isodense subdural hematomas.