Figure 4: Quantitative pulmonary perfusion scans in anterior (top and bottom left) and posterior (top and bottom right) views demonstrating decreased perfusion to the left lung (top – Pre) which improved markedly (bottom - Post) following stent placement in the left pulmonary artery. The right vs. left lung perfusion was of 73% vs. 27% changed to 56% vs. 44%, respectively following stent implantation.