Repeated T1 mapping in brain following clinical dosage of Teslascan

Introduction Manganese enhances MRI is increasingly used for exploring neuronal activity, tracing white matter tracts and for structural delineation of normal and pathological brain anatomy in animals in vivo [1]. Manganese is a Ca analogue and enters the cells via many different Ca channels. Depending on mode of administration different features of brain structure and function can be depicted. Unfortunately manganese has neurotoxic properties. Acute neuronal death is observed in response to high CNS concentrations of manganese, whereas neurodegeneration is found after prolonged intracellular accumulation of manganese. These neurotoxic effects hamper the use manganese enhances MRI in human neuroimaging. Teslascan (mangafodipir trinatrium, Amersham Health, Oslo, Norway) is a manganese based contrast agent clinically approved for diagnosing liver pathology and also used in cardiac MRI of tissue viability [2,3]. In the present study we explored the effect of one standard intravenous dose of Teslascan on T1 relaxation rate in the brain. The aim of the study was to investigate whether Teslascan leads to measurable changes in T1 relaxation and for how long such changes persist. If Teslascan in clinically approved dosage in combination with T1 mapping have sufficient sensitivity to allow detection of subtle differences in manganese enhancement, Teslascan could possibly be used for accurate spatial localization of regions with pathological increased or decreased neuronal activity in humans.