Encephalopathic cerebrovascular steal: dynamic CT of arteriovenous malformations.

Arteriovenous malformations and the clinical symptoms they engender are due in large part to the cerebrovascular steal intimately associated with these lesions. Intravenous dynamic computed tomography was utilized in a series of 10 patients harboring cranial vascular malformations of varying size and location in an effort to further elucidate the pathophysiology and extent of the arteriovenous shunt in pre-hemorrhagic (8 subjects) and post-hemorrhagic (2 subjects) clinical situations. Perfusion abnormalities were identified locally as well as distant from the nidus of the lesion, both intra- and extra-axially. The technique of dynamic computed tomography in this study group confirms past observations regarding the steal phenomenon and reveals aberrant perfusion states which were previously unknown.