Is There Long-term Signal Intensity Increase in the Central Nervous System on T1-weighted Images after MR Imaging with the Hepatospecific Contrast Agent Gadoxetic Acid? A Cross-sectional Study in 91 Patients.

Purpose To evaluate whether there is T1-weighted signal intensity (SI) increase in the dentate nucleus (DN) and globus pallidus (GP) in relation to the middle cerebellar peduncle (MCP), pons, and thalamus after repeated administration of the liver-specific contrast agent gadoxetic acid. Materials and Methods This was an institutional review board-approved, prospectively conducted (written informed consent acquired), cross-sectional study performed in a consecutively selected patient group (n = 91; patients received one to 37 doses of gadoxetic acid) and a control group (n = 52; subjects had never received injections of gadolinium-based contrast agent) examined with a standard T1-weighted two-dimensional spin-echo pulse sequence of the brain at 1.5 T. DN/MCP, DN-to-pons, GP-to thalamus, and GP-to-cerebrospinal fluid ratios were measured and compared by using the nonparametric Kruskal-Wallis test, corresponding pairwise tests, and Spearman correlation. Results DN/MCP (ρ = 0.51, P < .0001) and DN-to-pons (ρ = 0.41, P = .0001) ratios correlated positively with the number of previous administrations of gadoxetic acid. DN/MCP and DN-to-pons ratios were significantly different between control subjects (medians of 1.016 and 1.034, respectively) and patients with more than 10 gadoxetic acid administrations (1.038 [P < .0001] and 1.053 [P = .0100], respectively), whereas no significant difference was found in the groups with five to 10 (1.029 [P = .053] and 1.044 [P = .072], respectively) and fewer than five (1.014 [P = .420] and 1.030 [P = .595], respectively) gadoxetic acid administrations. GP-to-thalamus ratios differed significantly between the study and control groups (P < .0001), whereas no significant correlation was found for GP-to-thalamus ratios and number of gadoxetic acid administrations (ρ = 0.13, P = .2304). Conclusion Results show a significant correlation between the number of gadoxetic acid administrations and the increase of SI in the DN, which is likely due to gadolinium retention. © RSNA, 2017.