Study On Correlation Between The High Signal Intensity Of Unenhanced T1WI In Intracerebral Nuclei And The Administrations Of Gadolinium-based Contrast Agent

Objective:To investigate the development of signal intensity on unenhanced T1-weighted MR scans of cerebral nucleus and its correlation with the administrations of Gadopentetate dimeglumine and other clinical factors.Methods:38 patients who received repeated（≥3times）brain MRI enhanc-ement examinations with linear gadolinium-based contrast agent,Gadopentetate dimeglumine,from June 2017 to May 2020 in the Second Affiliated Hospital of Guangxi Medical University were analyzed retrospectively.The signal intensity（SI）of dentate nucleus（DN）,globus pallidus（GP）and frontal white matter on unenhanced T1-weighted MR images were measured before the injection of gadopentetate dimeglumine at the first and last enhanced examinations.Calculate the following values:（1）The SI ratio of the dentate nucleus to the frontal white matter(SI_DN),and the SI ratio of the globus pallidus to the frontal white matter(SI_GP).（2）The difference of SI ratio between the first and last examination(SI_DN、SI_GP).A one-sample T test was used to test whether the SI_DNand SI_GPare differ from 0.And multiple linear regression analyses were used to examine the correlation between changes of SI ratio in dentate nucleus and globus pallidus and the numbers of GBCA administrations,the mean interval time,the time interval from the first to final examination and other clinical factors.Results:（1）The difference between the T1WI signal intensity ratio of the last and the first examination on dentate nucleus and globus pallidus were both greater than zero（P<0.001）.（2）There was a significant linear correlation between SI_DNand the numbers of gadolinium contrast agent that patient had used[P<0.001,R value=0.655],and there was a weaker linear correlation between SI_GPand the numbers of gadolinium contrast agent patient had used[P=0.008,R value=0.426].There was no correlation between the signal changes of the dentate nucleus and the mean interval time,the time interval from the first to final examination and other clinical factors（P>0.05）,which is the same as the globus pallidus.Conclusion:The signal intensity in dentate nucleus and globus pallidus are increased on unenhanced T1-weighted images after multiple administrations of GBCA.And the increased signal intensity of T1WI on dentate nucleus and globus pallidus is linearly correlated with the numbers of gadolinium contrast agent that patients had used,but it was not related to the time interval from the first to final examination,the mean interval time and other clinical factors.