Intravenous digital subtraction angiography in patients with carotid territory ischemia: a prospective trial.

To evaluate the place of intravenous digital subtraction angiography (IV-DSA) in the investigation of patients with carotid territory ischemia, we have compared the IV-DSA and conventional angiographic (CA) findings in 40 patients in a prospective study. Arterial disease was assessed by grading stenosis from zero (normal artery) to six (complete occlusion) and recording any luminal ulceration. In 59 of 66 bifurcations imaged by both techniques, the IV-DSA evaluation of any internal carotid artery origin disease was within one grade of the CA assessment, with three false negatives and four false positives. Luminal ulceration was less reliably predicted, and two clinically important middle cerebral artery lesions were missed by IV-DSA. In 11 patients who had carotid endarterectomy, there was a good correlation between surgical, CA, and IV-DSA findings, although some ulcerations were not detected by either angiographic technique. These results suggest that IV-DSA is a sensitive technique for detection of carotid bifurcation stenosis when the study is of good quality, but that intracranial lesions may be missed.