Manganese-Enhanced Magnetic Resonance Imaging in Healthy Volunteers and People With Multiple Sclerosis

Objective The original goals of this pilot study were to assess whether: (1) manganese-enhanced magnetic resonance imaging (MEMRI) using mangafodipir trisodium, a contrast agent that enters the intracellular compartment, can detect multiple sclerosis-related tissue damage in the retina, optic nerve, and brain; and (2) the MRI effects of manganese are detectable in the basal ganglia one month following administration. With amendment F, the retina and optic nerve portions of the study have been eliminated, and we have modified our focus to examination of participants with multiple sclerosis and MRI evidence of abnormal permeability to gadolinium. In these individuals, mangafodipir may allow assessment of brain connectivity that is not possible to achieve with a gadolinium-based contrast agent, which remains in the extracellular space. Study Population Up to 15 healthy volunteers and up to 15 participants with multiple sclerosis. Design The first phase of the study involved healthy volunteers and focuses on optimizing our imaging protocol. The second phase studies participants with multiple sclerosis. With amendment F, the focus has shifted to evaluating participants with multiple sclerosis and evidence of gadolinium enhancement on contrast-enhanced brain MRI. We have completed enrollment of 15 healthy volunteers. With Amendment G, we will remove references to the enrollment and screening procedures for healthy volunteers. Outcome Measures The primary outcome measure is T1-weighted signal intensity, measured: (1) in the retina, optic nerve, and brain at early time points after mangafodipir administration; and (2) in the basal ganglia, cerebral cortex, and whole brain one month following administration.