[Correlation between high signal intensity in cerebrum nucleus on unenhanced T 1 -weighted MR images and number of previous gadolinium-based contrast agent administration].

OBJECTIVE: To explore the correlation between the number of previous gadolinium-based contrast agent administrations and high signal intensity (SI) in the cerebrum nucleus on unenhanced T1 -weighted magnetic resonance images.

METHODS: Thirty-nine patients who previously underwent at least three contrast-enhanced brain MRI examinations were enrolled in the study. The right globus pallidus, right thalamus, right dentate nucleus, pons and white matter of right frontal lobe were selected as region of interests (ROI). The mean SIs of the ROI were measured on unenhanced T1 -weighted images. The SI ratios of globus pallidus, right thalamus, right dentate nucleus and pons to white matter were calculated, respectively. The correlation of SI ratio variation with the number of previous contrast agent administration and clinical features was analyzed with Spearman analysis.

RESULTS: The dentate nucleus-to-white matter SI ratios of the last and first MRI scan were 1.113±0.136 and 1.014±0.096( P <0.01), respectively; while the SI ratio differences between the last and first MRI scan of globus pallidus-to-white matter, the thalamus-to-white matter and the pons-to-white matter were not significant (all P >0.05). The dentate nucleus-to-white matter SI ratio was correlated with the number of previous gadolinium-based contrast agent administrations ( r =0.329, P <0.05), but not with age, sex, underlying disease, treatment and history of diabetes (all P >0.05).

CONCLUSIONS: High SI in the dentate nucleus on unenhanced T1 -weighted images may be a consequence of the number of previous gadolinium-based contrast agent administrations.