Manganese enhancement in non-CNS organs.
Manganese-enhanced magnetic resonance imaging (MEMRI) is a novel imaging technique capable of monitoring calcium influx, in vivo. Manganese (Mn2+) ions, similar to calcium ions (Ca2+), are taken up by activated cells where their paramagnetic properties afford signal enhancement in T(1)-weighted MRI methodologies. In this study we have assessed Mn2+ distribution in mice using magnetization-prepared rapid gradient echo (MP-RAGE) based MRI, by measuring changes in T(1)-effective relaxation times (T(1)-eff), effective R(1)-relaxation rates (R(1)-eff) and signal intensity (SI) profiles over time. The manganese concentration in the tissue was also determined using inductively coupled plasma atomic emission spectrometry (ICP-AES). Our results show a strong positive correlation between infused dose of MnCl2 and the tissue manganese concentration. Furthermore, we demonstrate a linear relationship between R(1)-eff and tissue manganese concentration and tissue-specific Mn2+ distribution in murine tissues following dose-dependent Mn2+ administration. This data provides an optimized MnCl2 dose regimen for an MP-RAGE based sequence protocol for specific target organs and presents a potential 3D MRI technique for in vivo imaging of Ca2+ entry during Ca2+-dependent processes in a wide range of tissues.
Lee
Li-Wen
LW
Metabolic and Molecular Imaging Group, MRC Clinical Sciences Centre, Hammersmith Hospital Campus, Imperial College London, London, UK.
So
Po-Wah
PW
Price
Anthony N
AN
Parkinson
James R C
JR
Larkman
David J
DJ
Halliday
Jane
J
Poucher
Simon M
SM
Pugh
John A T
JA
Cox
Alan G
AG
McLeod
Cameron W
CW
Bell
Jimmy D
JD
D000818:Animals; D002712:Chlorides / Q000008:administration & dosage / Q000378:metabolism; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008345:Manganese / Q000737:chemistry / Q000378:metabolism; D017895:Manganese Compounds / Q000008:administration & dosage / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D014018:Tissue Distribution
D002712:Chlorides; D017895:Manganese Compounds; D008345:Manganese; C025340:manganese chloride