Computerized tomography in vascular malformations of the brain.

Computerized tomography scans of 166 patients - 99 cases with 117 aneurysms, and 67 cases with angiomatous malformations - were reviewed and correlated with angiographic and clinical findings. An intracranial hemorrhage was identified by CT scan in 103 patients, in 60 cases with aneurysms (17 only subarachnoid, 43 intracerebral), and in 43 cases with angiomas (6 only subarachnoid, 37 intracerebral). The source of hemorrhage was diagnosed with varying degrees of certainty with CT scan in 12 (12%) cases with aneurysms and in 27 (40%) cases with angiomas. Further CT findings were low density lesions in 18 cases indicating vasogenic edma, and calcifications in 10 angiomas. Intravenous infusion of contrast material was necessary to distinguish smaller aneurysms and angiomas. CT scan demonstrated the presence and location of thrombosed portions of giant aneurysms; these findings were less apparent with angiography. In 29 angiomas of medium or large size (macroangiomas) the malformation was demonstrated with CT scan in 25 (86%) cases and with angiography in 26 cases. 3 angiographically occult angiomas were diagnosed with CT as low density lesions and misinterpreted as gliomas. In all 36 microangiomas only the hemorrhage was precisely diagnosed with CT. The microangioma was identified angiographically in 24 cases and histologically in 21. In Sturge-Weber's disease the calcifications may be seen earlier with CT than with skull x-ray.