Computed tomography and ruptured intracranial aneurysm in acute stage (author's transl)

Abstract

We analyzed 87 CT scannings from 74 cases performed between the onset day and the 14th day after the last episode of SAH in preoperative state to evaluate characteristic findings of SAH in acute stage and sequential changes of CT findings. Locations of ruptured aneurysms were: anterior communicating artery (31), internal carotid artery (20), middle cerebral artery (19), anterior cerebral artery (2), and vertebro-basilar artery (2). EMI scanner CT-1000 and recently CT-1010 were used for scanning. Attenuation of extravasated blood occured after the 4th day, and became more particular at the 2nd week on CT. Within 3 days after onset, diagnostic value to locate aneurysm was about 70%/ of all cases, but this fell into 11 % at the 2nd week. On the 2nd week after onset, we could see secondary changes due to SAH, especially the influence of vasospasm. These were brain swelling, cerebral infarction and ventricular enlargement. At the first week of onset, extravasated blood still remained as high absorption areas in high percentage, and the influence of vasospasm appeared only in a few cases on CT. (1) Subarachnoid hematoma, (2) intraventricular hematoma, (3) intracerebral hematoma and(4) ventricular enlargement were selected as indicators of acute stage SAH. These findings were scored from “0” to “3” according to severity and were totaled. We termed this total score as the “CT score.” CT score correlated well with the severity and results of patients at discharge. There was a tendency to develop vasospasm corresponding to the qrade of subarachnoid hematoma. CT was very useful in treatment, especially in determining timing and approach of operation. Our principle in treating SAH patients is to execute radical operation as early as possible (within 3 days after onset if possible) to prevent rerupture, evacuate subarachnoid hematoma and intracerebral hematoma at the same time, and also to continuously perform ventricular drainage and external decompression if necessarily. We concluded that computed tomography was useful in diagnosis, estimation of prognosis, and also in treatment of SAH patients due to ruptured intracranial aneurysm in the acute stage.