Monitoring neovascularization of intraportal islet grafts by dynamic contrast enhanced magnetic resonance imaging.
Fifteen thousand youths are diagnosed yearly with type 1 diabetes mellitus. Pancreatic islet transplantation has been shown clinically to provide short-term (~1 year) insulin independence. However, challenges associated with early vascularization of transplanted islet grafts and long-term islet survival remain. We utilized dynamic contrast enhanced magnetic resonance imaging (DCE MRI) to monitor neovascularization of islets transplanted into the right lobe of the liver in a syngeneic mouse model. The left lobe received no islets and served as a control. DCE data were analyzed for temporal dynamics of contrast (gadolinium) extravasation and the results were fit to a Tofts two-compartment exchange model. We observed maximal right lobe enhancement at seven days post-transplantation. Histological examination up to 28 days was used to confirm imaging results. DCE-derived enhancement strongly correlated with immunohistochemical measures of neovascularization. To our knowledge these results are the first to demonstrate, using a FDA approved contrast agent, that DCE MRI can effectively and non-invasively monitor the progression of angiogenesis in intraportal islet grafts.
Chan
Nathaniel K
NK
Islet Transplant Laboratory; Department of Pediatrics; Loma Linda University School of Medicine; Loma Linda, CA USA.
Obenaus
Andre
A
Tan
Annie
A
Sakata
Naoaki
N
Mace
John
J
Peverini
Ricardo
R
Chinnock
Richard
R
Sowers
Lawrence C
LC
Hathout
Eba
E