A prospective study of carbon dioxide-digital subtraction vs standard contrast arteriography in the evaluation of the renal arteries.

OBJECTIVE

To compare carbon dioxide-digital subtraction arteriographic (CO2-DSA) images of renal artery anatomy with standard iodinated contrast arteriographic (ICA) images.

DESIGN

One hundred patients with vascular disease who required abdominal aortography were evaluated by both CO2-DSA and ICA modalities. Two blinded readers interpreted arteriograms for the degree of renal artery stenosis, and a third reader was employed to resolve differences in reader interpretations.

SETTING

University medical center.

MAIN OUTCOME MEASURES

The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were calculated for the ability of CO2-DSA to demonstrate a 60% or greater stenosis of the main renal artery; kappa values for CO2-DSA and ICA were calculated to assess intraobserver variability.

RESULTS

Of the 200 main renal arteries imaged, 17 (9 by means of CO2-DSA), 8 means of ICA) were eliminated because of inadequate visualization of the renal artery. In identifying a renal artery stenosis of 60% or greater, CO2-DSA had a sensitivity of 0.83, specificity of 0.99, positive predictive value of 0.94, and negative predictive value of 0.98. The overall accuracy was 0.97. The kappa was 0.75 for CO2-DSA and 0.70 for ICA, hence, the variation in the interpretations of CO2-DSA and ICA were comparable.

CONCLUSION

Images by means of CO2-DSA accurately reflect pathologic changes in renal arteries and are thus useful in the diagnosis of clinically occult occlusive renal artery disease in patients at risk of contrast medium-related nephrotoxicity.