T1 signal intensity changes in dentate nucleus and lentiform nucleus on unenhanced T1-weighted MR images after intravenous administration of linear and macrocyclic contrast gadolinium based agents

Purpose: Our aim is to establish a connection between intravenous injections of gadolinium based contrast agents (GBCAs) and T1 signal intensity increase in dentate nucleus and lentiform nucleus. Material and Methods: The population of the study consisted of 166 patients who underwent brain MRI (456 total MRI scans) after iv injection of a gadolinium based contrast agent (linear: Gadodiamide, Gadopentetic acid/Gadopentate dimeglumine and macrocyclic: Gadoteric acid, Gadobutrol), at least twice between September 2013 and April 2017, and a control group which consisted of 50 patients who had never received GBCAs intravenously. Signal intensity was measured in the lentiform nucleus and dentate nucleus bilaterally on unenhanced T1weighted images for all the groups. Statistical analysis of the acquired measurements was performed. Results: Patients who received Gadodiamide presented a mean T1 signal increase of 46.5 units (to SD ± 74) of the initial dentate nucleus signal; compared the control group the difference was statistically significant (p=0.034). A statistically significant T1 signal increase in lentiform nucleus is associated to administration of Gadobutrol, with a mean signal intensity increase of 23.6 units (SD ± 47.9) and statistical significance (p=0.43). No increase in signal intensity was noted for Gadoteric acid and Gadopentetic acid. Conclusions: Intravenous administration of Gadodiamide and Gadobutrol results in signal intensity increase in lentiform nucleus and dentate nucleus.