Abstract 10956: In-vivo Tracking of Mononuclear Cells for Therapeutic Neovascularization in Myocardial Infarction: Comparison Between Manganese-Enhanced Magnetic Resonance Imaging and Single Photon Emission Computed Tomography
Autologous transplantation of bone marrow or peripheral blood mononuclear-cells (MNCs) has been applied as a strategy for therapeutic angiogenesis after limb ischemia and myocardial infarction. In vivo tracking of MNCs with magnetic resonance imaging (MRI) has attempted to visualize the long term regenerative therapeutic effects and the localization of migrated cells at high spatial resolution in living tissues such as skeletal muscle, heart, and brain. Manganese (Mn2+) is known to be an essential element for living organisms and there has been a recent renewed interest in Mn2+ as a useful ‘positive' MRI contrast agent. We successfully established a Methods to label MNCs with Mn2+ (Mn-MNCs) and performed longitudinal observation of Mn-MNCs in a rat model of myocardial infarction with 7-tesla MRI. Mn-MNCs or saline were intramuscularly injected into a border zone of the ischemic myocardium and were evaluated once a week by T1-weighted imaging. We also injected MNCs labeled with 111-indium oxine (111In-MNCs) into the ischemic myocardium of rats and observed the progress with single-photon emission computed tomography (SPECT). The transplanted Mn-labeled MNCs were typically detected as a “double-layered” structure having a negative core with surrounding positive enhancement immediately after the intramuscular administration, and those were clearly observed for up to 57 days in T1-weighted cardiac MRI (Figure). The dynamics and volume enhanced by the presence of the Mn-labeled MNCs agreed well with the SPECT imaging of 111In-MNCs in the ischemic myocardium. This Mn-enhanced method enables visualization of the transplanted area at 150–175 μm in-plane spatial resolution and allows the migration of labeled-MNCs to be observed for long periods in the same animal. Mn2+-enhanced cellular MRI promises to be a useful technique for the quantitative evaluation of cell tracking.
- © 2010 by American Heart Association, Inc.