Contrast-enhanced carotid MR angiography with commercially available triggering mechanisms and elliptic centric phase encoding

OBJECTIVE. The technical feasibility of contrast-enhanced MR angiography of the carotid arteries was evaluated with routinely available timing sequences and elliptic centric acquisition. The image quality of the contrast-enhanced MR angiography was compared with that of multiple overlapping thin-section acquisition MR angiography (MOTSA MR angiography). SUBJECTS AND METHODS. Sixty-three patients were enrolled. A 2-mL test bolus and commercially available software were used to time the gadolinium bolus. High-resolution contrast-enhanced MR angiography was performed with elliptic centric acquisition. RESULTS. The average time of bolus arrival was 17.3 sec (range, 12-25 sec). In 60 of the 63 patients, we had excellent or good visualization of the carotid bifurcation using contrast-enhanced MR angiography with little or no venous contamination. Two observers ranked delineation of stenosis and morphology of proximal internal carotid artery and overall diagnostic confidence statistically significantly higher for contrast-enhanced MR angiography compared with MOTSA. Ulceration, length of stenosis, and slow how distal to a critical stenosis were better depicted with contrast-enhanced MR angiography than with MOTSA. Venetian blind artifact, saturation of slow or in-plane flow, and artifactual narrowing in carotid artery kinks plagued MOTSA but were not seen on contrast-enhanced MR angiography. MOTSA was graded superior to contrast-enhanced MR angiography in nine of 120 carotid bifurcations analyzed. CONCLUSION. High-resolution carotid contrast-enhanced MR angiography is technically feasible. We found a 95% success rate using commercially available hardware and software. The image quality with carotid contrast-enhanced MR angiography has improved so that it is equal or superior to the longer MOTSA in most patients.