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Comparison of in leakage from labeled endocardial and epicardial cells: impact on modeling viability of cells to be transplanted into myocardium.

Blackwood KJ, Sykes J, Deans L, Wisenberg G, Prato FS - Int J Mol Imaging (2011)

Bottom Line: Results.The epicardial and endocardial kinetics were not significantly different (Epi: 1286 ± 253; Endo: 1567 ± 470 hours P = .62).Conclusion.

View Article: PubMed Central - PubMed

Affiliation: Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, ON, Canada N6A 4V2.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Images of 111In following epicardial delivery into normal myocardium following left thoracotomy. (Left) Sagittal SPECT/CT slice showing site of 111In injection in the myocardium. (Right) Wholebody 111In scans of canine demonstrating 111In activity at the injection site (day 0–15 wholebody scans are scaled to a maximum pixel value).
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fig1: Images of 111In following epicardial delivery into normal myocardium following left thoracotomy. (Left) Sagittal SPECT/CT slice showing site of 111In injection in the myocardium. (Right) Wholebody 111In scans of canine demonstrating 111In activity at the injection site (day 0–15 wholebody scans are scaled to a maximum pixel value).

Mentions: The myocardial retention of 111In-tropolone following injection into canine myocardium was determined from serially acquired wholebody images, and ratios of heart to wholebody (H : WB) activity were calculated. Ratios (expressed as a percentage) were similar with the Epi group and Endo group having H:WB ratios of 48 ± 5% and 50 ± 4% (P = .902) respectively, directly following injection, indicating that the endocardial injection was as effective in tracer delivery as the epicardial injection within the specified time window of 30–40 min postinjection. Table 1 shows the change in ratios for each animal for the first 5 hours following injection. Wholebody images from representative canines acquired after injection (Day 0 to 3 weeks) show the localization of 111In within the myocardial tissue as confirmed by SPECT/CT following epicardial (Figure 1) and endocardial (Figure 2) injection. Images also show the biodistribution of 111In within the liver, kidneys, and bladder. One animal in each of the groups had a lower ratio likely due to some injections into the left ventricular cavity rather than myocardium.


Comparison of in leakage from labeled endocardial and epicardial cells: impact on modeling viability of cells to be transplanted into myocardium.

Blackwood KJ, Sykes J, Deans L, Wisenberg G, Prato FS - Int J Mol Imaging (2011)

Images of 111In following epicardial delivery into normal myocardium following left thoracotomy. (Left) Sagittal SPECT/CT slice showing site of 111In injection in the myocardium. (Right) Wholebody 111In scans of canine demonstrating 111In activity at the injection site (day 0–15 wholebody scans are scaled to a maximum pixel value).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3094859&req=5

fig1: Images of 111In following epicardial delivery into normal myocardium following left thoracotomy. (Left) Sagittal SPECT/CT slice showing site of 111In injection in the myocardium. (Right) Wholebody 111In scans of canine demonstrating 111In activity at the injection site (day 0–15 wholebody scans are scaled to a maximum pixel value).
Mentions: The myocardial retention of 111In-tropolone following injection into canine myocardium was determined from serially acquired wholebody images, and ratios of heart to wholebody (H : WB) activity were calculated. Ratios (expressed as a percentage) were similar with the Epi group and Endo group having H:WB ratios of 48 ± 5% and 50 ± 4% (P = .902) respectively, directly following injection, indicating that the endocardial injection was as effective in tracer delivery as the epicardial injection within the specified time window of 30–40 min postinjection. Table 1 shows the change in ratios for each animal for the first 5 hours following injection. Wholebody images from representative canines acquired after injection (Day 0 to 3 weeks) show the localization of 111In within the myocardial tissue as confirmed by SPECT/CT following epicardial (Figure 1) and endocardial (Figure 2) injection. Images also show the biodistribution of 111In within the liver, kidneys, and bladder. One animal in each of the groups had a lower ratio likely due to some injections into the left ventricular cavity rather than myocardium.

Bottom Line: Results.The epicardial and endocardial kinetics were not significantly different (Epi: 1286 ± 253; Endo: 1567 ± 470 hours P = .62).Conclusion.

View Article: PubMed Central - PubMed

Affiliation: Imaging Program, Lawson Health Research Institute, 268 Grosvenor Street, London, ON, Canada N6A 4V2.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus