Computed tomography of the isodense subdural hematomas

Abstract

Most subdural hematoma with significantly differed attenuation from that of adjacent brain tissue can be accurately diagnosed by CT . Difficulty arises when the hematoma is isodense that is ex hibited similar attenuation to that of brain . Unilateral isodense subdural hematoma can be identified by indirect sign such as mass effect. Occasionally , the use of intravenous contrast material to aid in identifying isodense subdural hematomas has met with with variable success. Moreover , bilateral isodense subdural hematoma may be more difficult. We therefore considered it of intercst to evaluate the diagnostic efficiency of CT in isodense subdural he matomas.We have analysed 13 cases surgically provened cases of isodense subdural hematoma examined at Korea General Hospital from October 1981 10 April1982.The results were as follows:1. One hundred twenty seven cases of subdural hematomas were studied by CT , 13 cases (10 .2 %) of which were isodense 2 . The age distribution was from 29 years 10 69 years and mean age was 52 years. The sex ratio was 11 male to 2 female.3. Seven (53 .8%) of 13 cases has a h istory of head trauma. 4 . The lime interval which subdural hematoma became isodense was from 1 week to 4 months and peak time interval was from 1 week to 3 weeks.5. The precontrast CT scan of isodense subdural hematoma appeared shifting of midline structure, compression and deformity of the ventricles in all 13 cases , effacement of cerebral sulci in 10 cases (76 .9 %) and dilatation o f contralateral ventricles in 4 cases (30.8 %). 7. Bilateral isodense subdural hematomas were 2 (15 .4%) of 13 cases.