High-resolution carotid artery MRA. Comparison with fast dynamic acquistion and duplex ultrasound scanning

Abstract

Purpose: To determine whether the diagnostic accuracy of contrast-enhanced MR angiography (CE-MRA) of the carotid arteries is improved by using a slow-injection, high-resolution technique.

Material and methods: In 22 patients suspected to have internal carotid artery (ICA) stenosis at duplex ultrasound scanning (DUS), CE-MRA was performed both with a fast, dynamic (8 s/phase) and with a slower, high-resolution technique (scan time 2:20 min).

Results: There was conformity between the CE-MRA techniques regarding the degree of stenosis in 34/40 extracranial ICAs. In 3/6 discrepant cases, short occlusions were seen with the fast dynamic technique, whereas both the high-resolution CE-MRA technique and DUS showed patent vessels. There was an overall tendency toward higher stenosis grading with the dynamic technique. Overlying veins could be removed on a workstation in all high-resolution examinations.

Conclusion: The high-resolution carotid CE-MRA technique proposed herein seems to improve the diagnostic accuracy, at least for differentiation between high-grade stenoses and occlusions.