MRI Brain Signal Intensity and Relaxation Times in Individuals with Prior Exposure to Gadobutrol.

Purpose To perform follow-up brain MRI in volunteer participants who had previously received multiple doses of gadobutrol and to assess for changes in signal intensities and relaxation times. Materials and Methods This prospective study included 160 participants who received gadobutrol only between 2007 and 2017. The participants were separated into two groups, including participants with at least five contrast agent-enhanced examinations and normal kidney function (group 1) or at least one examination and impaired renal function (group 2). Control groups with normal and impaired renal function (groups 3 and 4) without history of contrast agent exposure were included for comparison. Unenhanced brain MRI was performed in 220 participants (76, 84, 25, and 35 participants in groups 1-4, respectively) with T1-weighted spin-echo and T1 and T2 mapping to determine visual signal intensity changes, signal intensity ratios (globus pallidus-to-thalamus and dentate nucleus-to-pons ratios), and T1 and T2 relaxation times. Results In groups 1 and 2, neither visual signal alterations nor differences in signal intensity ratio or T2 mapping were found. T1 mapping showed no changes for dentate nucleus, pons, and thalamus. However, shorter T1 relaxation times in the globus pallidus were found in group 1 compared with group 3 (difference of -26.2 msec; P = .002), which correlated with the number of previous gadobutrol doses in this group (P = .001). Conclusion In study participants who had previously received gadobutrol, brain MRI showed no differences relative to healthy control participants without gadobutrol exposure. However, quantitative T1 measurements might indicate gadolinium retention in the globus pallidus. © RSNA, 2018 Online supplemental material is available for this article.