TY - JOUR T1 - Appropriate Minimal Dose of Gadobutrol for 3D Time-Resolved MRA of the Supra-Aortic Arteries: Comparison with Conventional Single-Phase High-Resolution 3D Contrast-Enhanced MRA JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. DO - 10.3174/ajnr.A5176 AU - S.H. Bak AU - H.G. Roh AU - W.-J. Moon AU - J.W. Choi AU - H.S. An Y1 - 2017/05/04 UR - http://www.ajnr.org/content/early/2017/05/04/ajnr.A5176.abstract N2 - BACKGROUND AND PURPOSE: The development of nephrogenic systemic fibrosis and neural tissue deposition is gadolinium dose–dependent. The purpose of this study was to determine the appropriate minimal dose of gadobutrol with time-resolved MRA to assess supra-aortic arterial stenosis with contrast-enhanced MRA as a reference standard.MATERIALS AND METHODS: Four hundred sixty-two consecutive patients underwent both standard-dose contrast-enhanced MRA and low-dose time-resolved MRA and were classified into 3 groups; group A (a constant dose of 1 mL for time-resolved MRA), group B (2 mL), or group C (3 mL). All studies were independently evaluated by 2 radiologists for image quality by using a 5-point scale (from 0 = failure to 4 = excellent), grading of arterial stenosis (0 = normal, 1 = mild [<30%], 2 = moderate [30%–69%], 3 = severe to occlusion [≥70%]), and signal-to-noise ratio.RESULTS: The image quality of time-resolved MRA was similar to that of contrast-enhanced MRA in groups B and C, but it was inferior to contrast-enhanced MRA in group A. For the grading of arterial stenosis, there was an excellent correlation between contrast-enhanced MRA and time-resolved MRA (R = 0.957 for group A, R = 0.988 for group B, R = 0.991 for group C). The SNR of time-resolved MRA tended to be lower than that of contrast-enhanced MRA in groups A and B. However, SNR was higher for time-resolved MRA compared with contrast-enhanced MRA in group C.CONCLUSIONS: Low-dose time-resolved MRA is feasible in the evaluation of supra-aortic stenosis and could be used as an alternative to contrast-enhanced MRA for a diagnostic technique in high-risk populations.AbbreviationsCCAcommon carotid arteryCE-MRAcontrast-enhanced MRAGBCAgadolinium-based contrast agentTRICKStime-resolved imaging of contrast kineticsTR-MRAtime-resolved MRA ER -