Computed axial tomographic findings of subarachnoid hemorrhage

We report the characteristics of Computed Tomography (CT) findings about 45 subarachnoid hemorrhage (SAH) patients mainly due to ruptured aneurysms. They are from 21- to 70-year-old of age, 17 males and 28 females. Within the third week after the onset, extravasated blood appeared. High density area was found in 15 of 16 ruptured aneurysm patients (94%) on CT-scan performed within 3 days after the onset of SAH. High density areas are seen in patients of Hunt's grade III, IV, and V. Massive intraventricular hemorrhage (IVH) are found in patients of grade IV and V. In anterior communicating aneurysm hemorrhage of suprasellar cistern expands symmetrically to ambient cistern and anterior interhemispheric fissure. In distal anterior cerbral aneurysm hemorrhage involves anterior interhemispheric fissure. In internal carotid aneurysm hemorrhage involves suprasellar cistern Sylvian fissure of ruptured side and then expands to other basal cisterns. In middle cerebral aneurysm hemorrhage involves Sylvian fissure of ruptured side and makes intracerebral hematoma in temporal or frontal lobe at the rate of 75%. Aneurysm itself by contract enhancement (CE) was found in 8 of 9 cases. High density areas of lesion were seen in arterio-venous malformation and head trauma patients. IVH was seen in Moyamoya disease patients. The wider SAH is, the higher mortality is, IVH due to ruptured aneurysm signifies poor prognosis. We should perform CT-scan of SAH patients as soon as possible. We have to examine circle of Willis chiefly and do it by CE, if possible. (author)