Increased Signal Intensity in the Dentate Nucleus on Unenhanced T1-weighted Images is Related to Serial Gadobenate Dimeglumine Administrations

Purpose: To compare changes in signal intensity (SI) ratios of the dentate nucleus (DN) to pons and cerebrospinal fluid (CSF) on unenhanced T1-weighted MR images between the first and last MRI using the linear gadolinium based contrast agent (lGBCA) gadobenate dimeglumine. Materials and methods: The study was approved by the ethical committee of the University of Heidelberg (S-324/2014) and written informed consent was waived due to the retrospective character of the study. Fifty patients who underwent at least six consecutive MRI examinations with the exclusive use of gadobenate dimeglumine were retrospectively analyzed. The difference of DN-to-pons and DN-toCSF mean SI ratios on unenhanced T1-weighted images between the first and last examination was calculated. Results were compared to previously published data for gadopentetate dimeglumine and gadoterate meglumine. Results: SI ratio differences for DN-to-pons and DN-to-CSF were significantly greater than 0 (pons: 0.0399 [+ or -] 0.0307, p < 0.001; CSF: 0.1439 [+ or -] 0.1524, p < 0.001). No control variable consistently predicted the SI ratio difference across both DN-to-pons and DN-to-CSF ratio. No significant difference in SI increase between gadopentetate dimeglumine and gadobenate dimeglumine was found for the DNto-pons ratio (p = 0.906), while the DN-to-CSF ratio was significantly lower (p < 0.001) for gadobenate dimeglumine. DN-to-pons (p < 0.001) and DN-to-CSF (p = 0.017) ratio were both significantly higher for gadobenate dimeglumine than for gadoterate meglumine. Conclusion: Serial application of gadobenate dimeglumine leads to SI increase in the DN. Further studies are needed to clarify different potential of lGBCA to cause SI increase in the DN.