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Dose dependence and temporal evolution of the T 1 relaxation time and MRI contrast in the rat brain after subcutaneous injection of manganese chloride
Author(s) -
Shazeeb Mohammed Salman,
Sotak Christopher H.
Publication year - 2012
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24184
Subject(s) - choroid plexus , in vivo , mri contrast agent , manganese , subcutaneous injection , magnetic resonance imaging , contrast (vision) , chemistry , pharmacokinetics , medicine , nuclear magnetic resonance , nuclear medicine , pharmacology , central nervous system , radiology , biology , artificial intelligence , computer science , physics , microbiology and biotechnology , organic chemistry
Divalent manganese ion (Mn 2+ ) is a widely used T 1 contrast agent in manganese‐enhanced MRI studies to visualize functional neural tracts and anatomy in the brain in vivo. In animal studies, Mn 2+ is administered at a dose that will maximize the contrast, while minimizing its toxic effects. In rodents, systemic administration of Mn 2+ via intravenous injection has been shown to create unique MRI contrast in the brain at a maximum dose of 175 mg kg −1 . However, intravenous administration of Mn 2+ results in faster bioelimination of excess Mn 2+ from the plasma due to a steep concentration gradient between plasma and bile. By contrast, following subcutaneous injection (LD 50 value = 320 mg kg −1 ), Mn 2+ is released slowly into the bloodstream, thus avoiding immediate hepatic elimination resulting in prolonged accumulation of Mn 2+ in the brain via the choroid plexus than that obtained via intravenous administration. The goal of this study was to investigate MRI dose response of Mn 2+ in rat brain following subcutaneous administration of Mn 2+ . Dose dependence and temporal dynamics of Mn 2+ after subcutaneous injection can prove useful for longitudinal in vivo studies that require brain enhancement to persist for a long period of time to visualize neuroarchitecture like in neurodegenerative disease studies. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.