Dynamic contrast-Enhanced MRI of Pancreatic Islet Transplants

Abstract

Since its discovery in 1922, insulin has been the life-saving treatment for type 1 diabetes mellitus. As the disease is caused by the loss of insulin-producing pancreatic islets, transplantation of donor islets has the potential to not only supplement insulin replacement therapy but to cure type 1 diabetes. However, long-term insulin independence (\u3e 2 years post-transplant) remains a challenge partly due to low islet blood flow immediately following transplantation leading to hypoxic stress on islets. The goal of our studies is to improve islet engraftment by monitoring and promoting the regrowth and maturation of new islet blood vessels in a clinically applicable manner. The developed technique is based on intravascular injection of a FDA-approved contrast agent which leaks from and accumulates around permeable immature blood vessels. Rapidly acquired MRI scans following contrast administration can then show the location and extent of new vessel formations. Our studies showed dynamic contrast-enhanced MRI to be successful in determining a timeline for islet revascularization as well as evaluating the effectiveness of a hyperbaric oxygen-based engraftment-enhancing therapy. The results are an important step in advancing islet transplantation as a potential cure for type 1 diabetes