title: Uptake and retention of manganese contrast agents for PET and MRI in the rodent brain.
abstract: Manganese-enhanced magnetic resonance imaging (MRI) is an established neuroimaging method for signal enhancement, tract tracing, and functional studies in rodents. Along with the increasing availability of combined positron emission tomography (PET) and MRI scanners, the recent development of the positron-emitting isotope52Mn has prompted interest in the use of Mn2+as a dual-modality contrast agent. In this work, we characterized and compared the uptake of systemically delivered Mn2+and radioactive52Mn2+in the rat brain for MRI and PET, respectively. Additionally, we examined the biodistribution of two formulations of52Mn2+in the rat. In MRI, maximum uptake was observed one day following delivery of the highest MnCl2dose tested (60 mg/kg), with some brain regions showing delayed maximum enhancement 2-4 days following delivery. In PET, we observed low brain uptake after systemic delivery, with a maximum of approximately 0.2% ID/g. We also studied the effect of final formulation vehicle (saline compared with MnCl2) on52Mn2+organ biodistribution and brain uptake. We observed that the addition of bulk Mn2+carrier to52Mn2+in solution resulted in significantly reduced52Mn2+uptake in the majority of organs, including the brain. These results lay the groundwork for further development of52Mn PET or dual Mn-enhanced PET-MR neuroimaging in rodents, and indicate several interesting potential applications of52Mn PET in other organs and systems. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Christina L
authors.initials: CL
authors.lastname: Brunnquell
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Reinier
authors.initials: R
authors.lastname: Hernandez
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Graves
authors.affiliation: Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Ivy
authors.initials: I
authors.lastname: Smit-Oistad
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Nickles
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA.|Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Weibo
authors.initials: W
authors.lastname: Cai
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA. memeyerand@wisc.edu.|Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA. memeyerand@wisc.edu.
authors.forename: M Elizabeth
authors.initials: ME
authors.lastname: Meyerand
authors.affiliation: Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA. masatoshi.suzuki@wisc.edu.|Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA. masatoshi.suzuki@wisc.edu.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D002712:Chlorides; D003287:Contrast Media / Q000737:chemistry* / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging / Q000379:methods; D008345:Manganese / Q000737:chemistry / Q000493:pharmacokinetics*; D017895:Manganese Compounds; D064847:Multimodal Imaging / Q000379:methods*; D059906:Neuroimaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods; D011868:Radioisotopes / Q000737:chemistry / Q000493:pharmacokinetics; D051381:Rats; D014018:Tissue Distribution
chemical_list: D002712:Chlorides; D003287:Contrast Media; D017895:Manganese Compounds; D011868:Radioisotopes; D008345:Manganese; C025340:manganese chloride
keywords: manganese; manganese-enhanced magnetic resonance imaging (MEMRI); neuroimaging; positron emission tomography (PET); quantitative imaging