[Computed tomography of ruptured arteriovenous malformations in the acute stage (author's transl)]

Eighteen patients with angiographically proved intracranial arteriovenous malformation (AVM) were studied by computed tomography (CT) and their clinical features were reviewed at the same time. The pathophysiology of ruptured AVM in the acute stage was discussed. Seven of the 18 patients were performed CT scan within 7 days after the onset. Although all but one of the patients showed symptoms and signs suggestive of subarachnoid hemorrhage (SAH), intracerebral hematoma was demonstrated in all cases and two of them were accompanied by ventricular rupture. On the more, no high density lesion was demonstrated in cerebral cisterns by plain CT scan as seen in the acute stage of ruptured cerebral aneurysms. Six patients were performed contrast study within 7 days after the onset and showed no enhancement effect. On the contrary, nine of 10 patients performed contrast study more than 8 days after the onset showed enhancement effect. It has been commonly postulated that subarachnoid hemorrhage is the main pathophysiology of ruptured AVM. However, out study on CT scan of ruptured AVM demonstrated that intracerebral hematoma or ventricular hemorrhage is the chief underlying pathophysiology of ruptured AVM in the acute stage.