There has been controversy as to whether gadobutrol, one of the widely used macrocyclic gadolinium-based contrast agents, can lead to gadolinium retention after serial injections. Our aim was to validate whether serial administrations of gadobutrol can cause signal increase in the dentate nucleus (DN) and globus pallidus (GP) on unenhanced T1-weighted magnetic resonance (MR) images due to gadolinium retention.Materials and Methods
A total of 189 patients who had undergone at least 2 contrast-enhanced MR scans using only gadobutrol between August 2009 and August 2016 were retrospectively included. The DN–to–pons and GP-to-thalamus signal intensity (SI) ratio differences on unenhanced T1-weighted MR images were calculated by subtracting the SI ratios at the first MR images from those at the last MR images. One-sample t tests were used to evaluate whether the SI ratio differences differed from 0. Linear regression and Pearson correlations were performed to assess correlations between SI ratio differences and various confounding variables, including the number of MR scans, mean time interval between MR scans, age, sex, history of radiation therapy or chemotherapy, and renal and liver functions.Results
Patients underwent a mean of 5.9 ± 6.3 contrast-enhanced MR scans with a mean interval of 42.8 ± 49.5 weeks between the scans. Sixty-three patients underwent 6 or more MR scans, whereas 126 patients underwent fewer than 6 MR scans. Neither the DN-to-pons SI nor the GP-to-thalamus SI ratio differences differed significantly from 0, with mean values of −0.012 ± 0.115 (P = 0.148) and 0.012 ± 0.111 (P = 0.126), respectively.Conclusions
Serial administrations of gadobutrol did not result in signal increases in the DN or GP on unenhanced T1-weighted MR images due to gadolinium retention.