Fractionated manganese‐enhanced MRI

AbstractWe investigated the use of manganese‐enhanced MRI (MEMRI) with fractionated doses as a way to retain the unique properties of manganese as a neuronal contrast agent while lessening its toxic effects in animals. First, we followed the signal enhancement on T1‐weighted images of the brains of rats receiving 30 mg/kg fractions of MnCl2 · 4H2O every 48 h and found that the signal increased in regions with consecutive fractionated doses and ultimately saturated. Second, we used T1 mapping to test whether the amount of MRI‐visible manganese that accumulated depended on the concentration of manganese in the fractions. For a fixed cumulative dose of 180 mg/kg MnCl2 · 4H2O, increasing fraction doses of 6 × 30 mg/kg, 3 × 60 mg/kg, 2 × 90 mg/kg and 1 × 180 mg/kg produced progressively shorter T1 values. The adverse systemic health effects, including complications at the injection site and poor animal well‐being, also rose with the fraction dose. Thus, fractionated MEMRI can be used to balance the properties of manganese as a contrast agent in animals against its toxic effects. Published in 2007 by John Wiley & Sons, Ltd.

Fractionated manganese‐enhanced MRI Journal Articles