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

• Published in: International Journal of Molecular Imaging 2011, Vol.2011, p.188-195
• Main Authors: Blackwood, Kimberley J, Sykes, Jane, Deans, Lela, Wisenberg, Gerald, Prato, Frank S
• Format: Article
• Language: English
• ISSN: 2090-1712; 2090-1720
• DOI: 10.1155/2011/472375

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 (111)In 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 ((111)In-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: 1286 ± 253; Endo: 1567 ± 470 hours P = .62). Conclusion. The original epicardial estimate of leakage kinetics has been validated for use in endocardial injections.