Contrast enhanced MRA: do contrast agents with a higher T-1 relaxitivity improve the visualization of carotid artery stenoses?

Purpose: CE-MRA is a powerful tool for the non-invasive evaluation of carot id artery occlusive disease. However, due to certain drawbacks, it has not completely replaced DSA. The purpose of this study was to evaluate if Gd-BO PTA, a contrast agent with high T-1 relaxivity, can increase the diagnostic accuracy of CE-MRA. Material and Methods: The CE-MRA examinations of 54 co nsecutive patients were evaluated by two experienced radiologists, independ ently. The examinations of 27 patients were contrasted either with 20 mi Gd -BOPTA or with 20 mi Gd-DTPA. The reviewers were blinded to the contrast ag ent chosen and to the ultrasound results. They rated the overall image qual ity and the degree of the ICA stenoses. Results: For the estimation of the degree of the ICA stenoses there was a high interrater validity. In compari son to the ultrasound findings, 6 of 50 high-degree stenoses were underesti mated as moderate stenoses. In one of seven sonographically occluded vessel s, MRA revealed residual patency in the vessel lumen. It was not possible t o identify the contrast agent that was taken for a study. Subjective estima tion of the image quality (arterial contrast of the ICA, contrast of the ot her vessels, and general impression) did not significantly change with the contrast agent employed. Conclusion: The diagnostic accuracy of CE-MRA for the evaluation of internal carotid artery stenoses is not improved by Gd-BO PTA if identical volumina of contrast media are applied. The potential of t his contrast agent can be the reduction of the amount of contrast without l oss of diagnostic information. Further studies are necessary.