Haosen Zhang1, Qing Ye1,
Chih-Lung Chen2, Kevin Hitchens1, Wen-Yuan Hsieh3,
Li Liu1, Yijen Wu1, Lesley Foley1, Hsin-Hsin
Shen2, Jassy Wang2, Chien Ho1
1NMR Center for Biomedical Research,
Carnegie Mellon University, Pittsburgh, PA, United States; 2Biomedical
Engineering Laboratories, Industrial Technology Research Institute, Hsinchu,
Taiwan; 3Material and Chemical Research Laboratories, Industrial
Technology Research Institute, Hsinchu, Taiwan
The
aim of this study is to detect the migration and accumulation of macrophages
by in vivo MRI in a rat heart-lung transplantation model of acute rejection
using a sensitive nano-sized iron oxide particle (ITRI-IOP). After infusion
of the macrophages labeled in vitro with ITRI-IOP, punctuate spots of
hypointensity are observed on the myocardium of the transplant allograft
heart 24 hrs later. Ex vivo imaging and immunohistochemistry analysis of the
fixed allograft heart shows abundance of punctuated spots of hypointensity
that are caused by the iron-loaded macrophages, which is not shown in the
native heart of the same rat.