Intravenous DSA examination of patients with suspected cerebral ischemia

The authors analyzed the role of intravenous digital subtraction angiography (DSA), with neck and intracranial views as a definitive pretherapy study, in patients who had symptomatic cerebral ischemia. Eight-six patients, 25 of whom had subsequent carotid thromboendarterectomy, were examined. An adequte pretherapy intravenous DSA study allowed the authors to define each carotid bifurcation as either normal, having insignificant stenosis, or having significant stenosis, and the examination excluded significant tandem stenosis in the intracranial internal carotid arteries. Inadequate presurgical studies were predominantly due to plaque misregistration, inadequate projection, and superimposition that obscured the proximal internal carotid arteries. Selective carotid arteriography was performed in these patients prior to surgery. Inadequate studies prior to initiation of medical therapy were predominantly due to soft tissue misregistration artifact, and superimposition