Effect of Renal Function on Gadolinium-Related Signal Increases on Unenhanced T1-Weighted Brain Magnetic Resonance Imaging

Objectives The purpose of this study was to determine if renal function affects signal changes in the deep brain nuclei on unenhanced T1-weighted images after administration of linear gadolinium-based contrast agents (GBCAs). Methods An electronic medical records search of 2 large medical centers identified 25 patients who received linear GBCA while on hemodialysis and had unenhanced T1-weighted images of the brain before and after. The dentate-to-cerebellar peduncle (DCP) ratio, globus pallidus-to-mid thalamus (GPT) ratio, and choroid plexus-to-nearby white matter ratio were measured and compared with 25 age/sex/GBCA exposure-matched control patients with normal or near-normal renal function (estimated glomerular filtration rate >60 mL/min per 1.73 m(2)). Two additional control groups included 13 patients on hemodialysis without GBCA exposure and 13 age/sex-matched patients with estimated glomerular filtration rate greater than 60 mL/min per 1.73 m(2). Results Hemodialysis patients (n = 25) with an average of 1.8 linear GBCA administrations had a 4.9% mean increase (1.00 0.04 vs 1.05 +/- 0.05; P < 0.001) in DCP, which was greater than the 1.6% change (0.99 +/- 0.04 vs 1.00 +/- 0.05; P = 0.08) observed in matched controls (P = 0.01). There was no significant signal change in the DCP ratio in the 13 hemodialysis patients (0.99 +/- 0.04 vs 0.99 +/- 0.04; P = 0.78) and 13 age/sex-matched patients (0.99 +/- 0.02 vs 0.99 +/- 0.03; P = 0.78) who did not receive GBCA. The hemodialysis patients had a baseline GPT that was higher than nondialysis patients (P < 0.001). However, the GPT change after GBCA administration was not significantly different from controls. Increased signal in the choroid plexus on unenhanced T1-weighted images after GBCA administration was noted in hemodialysis patients (0.72 +/- 0.20 vs 0.86 +/- 0.23; P = 0.006); however, a multivariate analysis showed this to be primarily related to hemodialysis (P = 0.003) with only a trend toward relating to GBCA exposure (P = 0.07). Conclusions Hemodialysis patients receiving linear GBCA have greater dentate nucleus signal increases on unenhanced T1-weighted images, suggesting that renal function may affect the rate of gadolinium accumulation in the brain after linear GBCA-enhanced magnetic resonance imaging.