Intrathecal Contrast-Enhanced Magnetic Resonance Imaging-Related Brain Signal Changes Residual Gadolinium Deposition?

Objectives: There have been recent studies evaluating brain magnetic resonance imaging changes in patients with normal renal function, after intravenous administration of gadolinium-based contrast agents (GBCAs). Their findings were supported by histological evidence as well and brought a new vision concerning what needs to be learned to provide better patient care. In this report, we aim to present brain magnetic resonance imaging changes after intrathecal administration of a linear ionic agent (gadopentetate dimeglumine). Materials and Methods: We evaluated hyperintensities in the deep nuclei of the brain in 6 patients with normal renal function after intrathecal administration of a linear ionic GBCA, without other confounding intravenous GBCA administrations. For visual analysis, T1 signal hyperintensity of the globus pallidus (GP), putamen, pons, and dentate nucleus (DN) were scored on a 4-point scale. For quantitative analysis, using the unenhanced T1-weighted images oval regions of interests were placed within the DN, central pons, GP, and thalamus on different image slice positions. Results: On visual analysis, 5 patients had T1 signal hyperintensity of the DN and GP, whereas the DN/pons signal intensity and the GP/thalamus signal intensity were found to be increased in all 6. Conclusions: This observation not only adds to our fund of knowledge concerning biodistribution and pharmacokinetics of those agents, but also raises the question of a possible association with the glymphatic pathway.