Introduction: Gadolinium-based contrast agents (GBCAs) are routinely used in many clinical magnetic resonance (MR) imaging studies. Recent studies have demonstrated, progressively increased signal intensity in the globus pallidus (GP) and dentate nucleus (DN) on T1 weighted brain images obtained in patients undergoing repeated MR studies.
Purpose: To evaluate changes in signal intensity (SI) ratios of the globus pallidus (GP) and the dentate nucleus (DN) on unenhanced T1 weighted images after multiple administrations of macrocyclic gadolinium based contrast agents: Gadoterate meglumine (Dotarem) versus Gadobutrol (Gadavist), both being macrocyclic agents.
Materials and methods: Methods: This was a retrospective, institutional review board approved ,HIPAA-compliant study.
The study population included patients with primary CNS tumors, referred for MRI between 2008 and 2016. Patients were divided into two groups: Group 1 included 8 patients who underwent Gadoterate meglumine (dotarem) MR imaging, and group 2 included 5 patients who underwent Gadobutrol (Gadavist) enhanced MR imaging. Two radiologists conducted a quantitative analysis of unenhanced T1-weighted images by using region of interest measurements. The GP-to-thalamus (GP\TH) signal intensity ratio, DN to middle cerebellar peduncle (DN\MCP) signal intensity ratio and relative percentage change between the first and last examinations for each patient were calculated.
Results: Preliminary results revealed a trend towards increased GP \TH Ratio from 1.0975 to 1.115 following multiple Dotarem administrations in Group 1. In contrast, GP\TH signal intensity ratio decreased after multiple administrations of Gadavist in group 2 from 1.132 to 1.066. DN\MCP signal intensity ratio increased on both groups: group 1 from 0.836 to 0.987; group 2 from 1.036 to 1.064.
Conclusion: Current data suggests a trend towards increase in signal intensity ratio in DN\MCP. Signal intensity ratio is associated with multiple administrations of both Gadoterate meglumine (Dotarem) and Gadobutrol (Gadavist).
