Preliminary observation on the changes of T(1) weighted signal of globus pallidus after multiple intravenous injection of linear gadolinium contrast agent

Abstract

Objective: To explore the changes in signal intensity (SI) ratios of globus pallidus (GP) on unenhanced T(1)-weighted(T(1)WI)magnetic resonance imaging (MRI) scans between the first and last MRI using the linear gadolinium-based contrast agent (GBCAs) intravenously. Methods: Clinical and imaging data of 114 patients who underwent at least 4 consecutive enhanced MRI examinations at the Affiliated Hospital of Xuzhou Medical University between January 2016 and April 2018 were analyzed. The SI ratio of GP, thalamus and cerebrospinal fluid (CSF) were measured on unenhanced T(1)WI. The GP to thalamus SI ratio was calculated by dividing the SI in the GP by that in the thalamus, and so was the GP to CSF SI ratio. The difference of SI ratio in the same patient was analyzed by nonparametric tests, linear regression analysis was used to analyze clinical factors. Results: The SI ratio of GP-to-thalamus and GP-to-CSF after multiple enhancement were higher than before, and the difference was statistically significant. The SI ratio of GP-to-thalamus and GP-to-CSF before and after repeated contrast-enhanced were 1.036(1.010, 1.075), 1.104(1.074, 1.168); 4.215(3.590, 5.614), 5.409(4.213, 6.502), all P<0.01. The SI ratio differences showed a significant positive correlation with the number of enhanced examination(pons:b=0.023, P<0.01,CSF:b=0.279,P=0.034), and a significant negative correlation with the interval (pons: b=-0.002,P< 0.01, CSF: b=-0.023, P=0.039). There was no correlation with other clinical factors (all P>0.05). Conclusions: There is an increase in SI in the GP after serial injections of linear GBCAs, and there is a positive correlation with the times of enhanced examination, and a negative correlation with time interval.