Digital Subtraction Angiography of the Abdominal Aorta and Lower Extremities: Carbon Dioxide versus Iodinated Contrast Material

Purpose To compare the diagnostic value of carbon dioxide to that of iodinated contrast material for digital subtraction angiography of the abdominal aorta and lower extremities. Materials and Methods Thirty-five patients underwent comparative CO 2 and iodinated contrast material arteriography of the abdominal aorta and lower extremities. For each contrast study, three independent observers evaluated the degree of opacification and percentage of stenosis of each vessel, the degree of certainty of their observations, and the overall quality of the study. Data of CO 2 and iodinated studies were compared using analysis of variance for repeated measures. Interobserver and intertechnique agreements were estimated with Cohen's kappa and intraclass correlation coefficient. Results Iodine-based vascular opacification was superior to that with CO 2 in the central and distal arteries ( P =.02). The degree of certainty and overall quality score were higher for iodine than for CO 2 -based contrast studies ( P =.00001). The interobserver agreement for categorizing stenoses was higher for iodine as compared to CO 2 -based angiography. No significant difference was observed between the mean stenosis values obtained with CO 2 and iodine-based angiography in any segment. Intraclass correlation coefficient demonstrated a high degree of convergence of the two techniques for assessing the percentage of stenosis. Conclusion CO 2 can be used as an alternative to iodinated contrast material for obtaining arteriograms of the abdominal aorta and lower extremities for investigating atherosclerotic disease.