Effects of Cardiac Motion on 3D Contrast-Enhanced MR Angiography of the Carotid Arteries

Purpose: To determine the effect of cardiac-related carotid artery motion on the image quality of 3D contrast-enhanced MR angiography (CEMRA) in patients presenting with suspected carotid artery disease. Materials and Methods: Twenty patients with suspected carotid artery disease underwent cardiac-gated cinematic steady-state free precession of the carotid arteries followed by standard 3D CEMRA at 1.5 T. Using postprocessing, computer programs determined the degree of vessel wall dilation and translation across the cardiac cycle from the cinematic exam and related this to vessel wall sharpness in 3D CEMRA, which was determined objectively by computer analysis and subjectively by a panel of expert neuroradiologists. Results: In patients, across 40 arteries the average carotid vessel movement due to cardiac pulsation was 0.36 +/- 0.17 mm and translation 1.53 +/- 0.94 mm. When using computer analysis of sharpness, the mean carotid wall motion had a weak negative correlation with 3D CEMRA vessel sharpness (Pearson's correlation -0.23, P < 0.01). However, the same trend was not present from the radiological review. Conclusion: In standard 3D CEMRA in patients with suspected carotid artery disease, cardiac-related carotid movement was a statistically significant source of degradation in vessel sharpness, but did not appear to be clinically significant.