Nonsurgical management of an isolated interhemispheric subdural hematoma sequentially followed by CT

Using transaxial CT scan, we diagnosed a patient with head injury as having an isolated interhemispheric subdural hematoma, on the basis of the widening of the superior sagittal sinus. The diagnosis was confirmed by coronal views. The patient was managed nonsurgically and gradual reabsorption of the hematoma was documented by CT. During the latter stages of reabsorption, two parallel lines were noted on the transaxial views as the subdural collection became smaller and drew away from the sagittal sinus. We conclude that an unusual widening of the superior sagittal sinus on transaxial CT scan warrants suspecting an interhemispheric subdural hematoma. Because the hematoma may be obscured by the overlying clot, coronal views may also be valuable.