An investigation into the presence of gadolinium-related MRI signal changes in the dentate nucleus at Dunedin Public Hospital

Abstract

Gadolinium-based contrast agents (GBCAs) have been used relatively safely since the 1980’s to increase the diagnostic efficacy of magnetic resonance imaging. Recent studies have shown that gadolinium can be deposited in tissues such as the skin, bone and brain in patients with severe renal failure or those exposed to multiple administrations of linear gadolinium-based contrast agents. In the brain, gadolinium is deposited in the dentate nucleus, the globus pallidus and to a lesser extent in the pons, thalamus and cerebellum. The deposition of gadolinium can be seen on T1-weighted magnetic resonance images as an increase in signal intensity in tissues in which gadolinium is accumulated. The aim of this study is to determine whether an increase in T1-weighted signal intensity can be detected in the dentate nucleus of patients who have been administered multiple doses of the GBCA gadopentetate dimeglumine in the process of being scanned at the Dunedin Public Hospital. A further aim is to determine the most robust method with which to quantify any changes in signal intensity on T1-weighted magnetic resonance images related to the accumulation of gadolinium. T1-weighted signal intensities were measured in the dentate nucleus, pons, middle cerebral peduncle and temporalis muscle in patients exposed to multiple doses of gadopentetate dimeglumine. All signal intensities were measured relative to either the pons, middle cerebral peduncle or temporalis muscle. In these patients, no increase in T1-weighted signal intensity was observed in the dentate nucleus, which is inconsistent with other recently published research. The lack of statistically significant differences make any comparison of the reference tissues difficult. However, measurements in the temporalis muscle showed more variability, indicating that the temporalis muscle may be less suitable as a reference tissue. The fact that the observations in this study differ from other published research is most likely due to the use of T1-weighted fluid attenuated inversion recovery images to conduct the signal intensity measurements. Further studies comparing T1-weighted fluid attenuated inversion recovery and other T1-weighted sequences are required to empirically test this effect.