Table of Contents
International Journal of Molecular Imaging
Volume 2011, Article ID 472375, 8 pages
Research Article

Comparison of 111In Leakage from Labeled Endocardial and Epicardial Cells: Impact on Modeling Viability of Cells to Be Transplanted into Myocardium

1Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, ON, Canada N6A 4V2
2Department of Medical Biophysics, University of Western Ontario, London, ON, Canada N6A 3K7
3Division of Cardiology, London Health Sciences Centre, London, ON, Canada N6A 5W9

Received 1 August 2010; Revised 18 November 2010; Accepted 9 February 2011

Academic Editor: Farouc Jaffer

Copyright © 2011 Kimberley J. Blackwood et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Introduction. Previously we proposed a cellular imaging technique to determine the surviving fraction of transplanted cells in vivo. Epicardial kinetics using Indium-111 determined the Debris Impulse Response Function (DIRF) and leakage coefficient parameters. Convolution-based modeling which corrected for these signal contributions indicated that 111In activity was quantitative of cell viability with half-lives within 20 hrs to 37 days. We determine if the 37-day upper limit remains valid for endocardial injections by comparing previous epicardial cell leakage parameter estimates to those for endocardial cells. Methods. Normal canine myocardium was injected (111In-tropolone) epicardially (9 injections) or endocardially (10 injections). Continuous whole body and SPECT scans for 5 hours were acquired with three weekly follow-up imaging sessions up to 20–26 days. Time-activity curves evaluated each injection type. Results. The epicardial and endocardial kinetics were not significantly different (Epi: ; Endo: hours ). Conclusion. The original epicardial estimate of leakage kinetics has been validated for use in endocardial injections.