Can the inflammatory response be evaluated using 18F-FDG within zones of microvascular obstruction after myocardial infarction?

Unlabelled: Inflammation that occurs after acute myocardial infarction plays a pivotal role in healing by facilitating the creation of a supportive scar. (18)F-FDG, which is taken up avidly by macrophages, has been proposed as a marker of cell-based inflammation. However, its reliability as an accurate indicator of inflammation has not been established, particularly in the early postinfarction period when regional myocardial perfusion is often severely compromised.

Comparison of the myocardial clearance of endothelial progenitor cells injected early versus late into reperfused or sustained occlusion myocardial infarction.

Stem cell transplantation following AMI has shown promise for the repair or reduction of the amount of myocardial injury. There is some evidence that these treatment effects appear to be directly correlated to cell residence time. This study aims to assess the effects of (a) the timing of stem cell injection following myocardial infarction, and (b) flow milieu, on cell residence times at the site of transplantation by comparing three time points (day of infarction, week 1 and week 4-5), and two models of acute myocardial infarction (sustained occlusion or reperfusion).

Hybrid SPECT/cardiac-gated first-pass perfusion CT: locating transplanted cells relative to infarcted myocardial targets.

Purpose: A challenge with cardiac cell therapy is determining the location of cells relative to infarct tissue. As cells are viable following ¹¹¹In-labeling, and first-pass CT imaging can identify regions of myocardial infarction, we evaluated the feasibility of a SPECT/CT system to localize cells relative to infarcted myocardium in a canine model.

Methods: Ten canines underwent surgical ligation of the left-anterior-descending artery and endothelial progenitor cells labeled with ¹¹¹In-tropolone were transplanted endocardially or epicardially.

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

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.

In vivo SPECT quantification of transplanted cell survival after engraftment using (111)In-tropolone in infarcted canine myocardium.

Unlabelled: Current investigations of cell transplant therapies in damaged myocardium are limited by the inability to quantify cell transplant survival in vivo. We describe how the labeling of cells with (111)In can be used to monitor transplanted cell viability in a canine infarction model.

Methods: We experimentally determined the contribution of the (111)In signal associated with transplanted cell (TC) death and radiolabel leakage to the measured SPECT signal when (111)In-labeled cells were transplanted into the myocardium.

A method for quantitative cell tracking using SPECT for the evaluation of myocardial stem cell therapy.

Purpose: A promising SPECT-based method for evaluating stem cells therapy uses (111)In-labelled cells, transfected with a reporter gene. Cells are first transplanted to the infarct, and subsequently interrogated for transgenic expression using a systemic injection of an (131)I-labelled reporter probe. The method is impeded by the physical effects of scatter, (131)I/(111)In cross-talk, and attenuation.