This article is a U.S. Government work and is in the public domain in the U.S.A.
Fractionated manganese-enhanced MRI†
Article first published online: 18 OCT 2007
This article is a U.S. Government work and is in the public domain in the U.S.A. Published in 2007 by John Wiley & Sons, Ltd.
NMR in Biomedicine
Volume 21, Issue 5, pages 473–478, June 2008
How to Cite
Bock, N. A., Paiva, F. F. and Silva, A. C. (2008), Fractionated manganese-enhanced MRI. NMR Biomed., 21: 473–478. doi: 10.1002/nbm.1211
- Issue published online: 28 MAY 2008
- Article first published online: 18 OCT 2007
- Manuscript Revised: 26 JUN 2007
- Manuscript Accepted: 26 JUN 2007
- Manuscript Received: 12 JUN 2007
- Intramural Research Program of the NIH, NINDS
- central nervous system;
- contrast agent
We 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.