Scintigraphy of dogs injected with 99mTc-labeled adipose tissue-derived mesenchymal stem cells. Representative scintigraphy images are shown for animal 4 and were obtained either 1 (a) or 24 hours (b) after cell injection. The arrows point to single radioactive spots (color). Body contours were revealed by using a germanium flood source. Cells are located in the thoracic spine at both 1 and 24 h after transplantation. Transplanted cells remained at the injection site for the first 24 h after transplantation.