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.