Gadopentetate dimeglumine as a contrast agent in common carotid arteriography

BACKGROUND AND PURPOSE: Despite improvements in noninvasive imaging, some p atients with contraindications to iodine-based contrast material still requ ire angiography for the evaluation of carotid stenosis, Our aim was to asse ss the utility of gadopentetate dimeglumine as an intraarterial contrast ag ent in common carotid angiography. METHODS: Twelve patients with suspected carotid artery stenosis were enroll ed in the study. In addition to the standard injection sequences with iohex ol, common carotid arteriograms were obtained after administration of gadop entetate dimeglumine. Neurologic status and vital signs were monitored duri ng and for 6 hours after the examination. For each injection, five independ ent observers, blinded to the contrast agent used, measured the percentage of carotid stenosis and assessed their confidence in grading the stenosis, the overall quality of the examination, and, in cases of decreased quality, the reason(s) for it. Statistical analysis was done with paired and unpair ed t-tests with equal variances. RESULTS: No patient had an adverse clinical outcome, and measurements of ca rotid artery stenosis showed no statistically significant differences betwe en the gadopentetate dimeglumine and iohexol examinations. Overall image qu ality and observer confidence in measurements of stenosis on the gadolinium -based studies were slightly but significantly lower than those of identica l iodine-based studies. CONCLUSION: Gadopentetate dimeglumine may be an alternative to iodine in se lected patients undergoing carotid angiography. Although overall image qual ity of the gadolinium studies is slightly inferior to that of the iohexol s tudies, measurements of carotid artery stenosis are similar for the two exa minations.