Dentate Nucleus Signal Intensity Decrease on T1-weighted MR Images after Switching from Gadopentetate Dimeglumine to Gadobutrol

Purpose: To determine if the increased dentate nucleus signal intensity following six or more doses of a linear gadolinium-based contrast agent (GBCA) (gadopentetate dimeglumine) changes at follow-up examinations performed with a macrocyclic GBCA (gadobutrol). Materials and Methods: This retrospective study included 13 patients with increased dentate nucleus signal intensity following at least six (range, 6-18) gadopentetate dimeglumine administrations who then underwent at least 12 months of follow-up imaging with multiple (range, 3-29) gadobutrol-enhanced magnetic resonance (MR) examinations. Dentate nucleus-to-pons and dentate nucleus-to-cerebellar peduncle signal intensity ratios were measured by two radiologists blinded to all patient information, and changes were analyzed by using the paired t test and linear regression. Results: The mean dentate nucleus-to-pons and dentate nucleusto-cerebellar peduncle signal intensity ratios increased after gadopentetate dimeglumine administration, from 0.98 +/- 0.03 to 1.10 +/- 0.03 (P < .0001) and from 0.98 +/- 0.030 to 1.09 +/- 0.02 (P < .0001), respectively. With gadobutrol, the mean dentate nucleus-to-pons and dentate nucleusto- cerebellar peduncle signal intensity ratios decreased to 1.03 +/- 0.03 and 1.02 +/- 0.04, respectively (P < .0001). With use of a mixed effects model linear regression allowing for each patient to have a different y intercept, mean dentate nucleus-to-pons and dentate nucleus-to-cerebellar peduncle signal intensity ratios decreased with follow-up time (dentate nucleus-to-pons: slope = -0.2% per month [95% confidence interval: -0.0024, -0.0015], R-2 = 0.58, P < .0001 for nonzero slope; dentate nucleusto- cerebellar peduncle: slope = -0.2% per month [95% confidence interval: -0.0024, -0.0015], R-2 = 0.61, P < .0001 for nonzero slope). Conclusion: Dentate signal intensity increased with at least six gadopentetate dimeglumine-enhanced MR examinations and decreased after switching from a linear (gadopentetate dimeglumine) to a macrocyclic (gadobutrol) GBCA. (C) RSNA, 2018.