In January of 2015, another study by Kanda et al was published online ahead of print in Radiology. The study, High Signal Intensity in Dentate Nucleus on Unenhanced T1-weighted MR Images: Association with Linear versus Macrocyclic Gadolinium Chelate Administration, evaluated MR images of 127 patients who had undergone contrast-enhanced brain MRIs at their institution in Japan. The images of nine patients (7.1%) showed hyperintensity in the Dentate Nucleus (DN) on unenhanced T1-weighted MR images – none of the patients had severe renal disease. Of those nine patients, 7 received only linear GBCA and 2 received both a linear and macrocyclic GBCA. The contrast agents were Magnevist and ProHance. After thorough analysis, the authors concluded that hyperintensity in the DN on unenhanced-T1 weighted MR images was associated with previous administration of the linear GBCA, but not with the macrocyclic GBCA.
The 7 patients that received Magnevist had between 2 to 11 administrations of contrast. It is noteworthy that hyperintensity was seen from as few as two doses of contrast. For the 2 patients that received both types of GBCA, one had four linear administrations and one macrocyclic; the other patient had five linear administrations and three macrocyclic administrations of contrast. Two of the patients had an eGFR between 30 and 60; the other seven had an eGFR greater than 60.
One of the 127 patients had received the macrocyclic contrast agent 15 times. Hyperintensity in the Dentate Nucleus was not observed on her unenhanced T1-weighted MR images. The patient had a glioblastoma and the DN was isointense on the unenhanced images.
Kanda and his colleagues suggested that further studies with a longitudinal design and larger number of patients are necessary.
For more information about Gadolinium and Gadolinium-Based Contrast Agents see Background on Gadolinium and Background on GBCAs in the Background section of our website.
Kanda, T., Osawa, M., Oba, H., Toyoda, K., Kotoku, J., Haruyama, T., … Furui, S. (2015). High Signal Intensity in Dentate Nucleus on Unenhanced T1-weighted MR Images: Association with Linear versus Macrocyclic Gadolinium Chelate Administration. Radiology, 140364. http://doi.org/10.1148/radiol.14140364.
Kanda, T., Ishii, K., Kawaguchi, H., Kitajima, K., & Takenaka, D. (2013). High Signal Intensity in the Dentate Nucleus and Globus Pallidus on Unenhanced T1-weighted MR Images: Relationship with Increasing Cumulative Dose of a Gadolinium-based Contrast Material. Radiology, 131669. doi:10.1148/radiol.13131669. Retrieved from http://pubs.rsna.org/doi/abs/10.1148/radiol.13131669