title: Use of [18F]FDG Positron Emission Tomography to Monitor the Development of Cardiac Allograft Rejection.
abstract: BACKGROUND
  Positron emission tomography (PET) has the potential to be a specific, sensitive and quantitative diagnostic test for transplant rejection. To test this hypothesis, we evaluated F-labeled fluorodeoxyglucose ([F]FDG) and N-labeled ammonia ([N]NH3) small animal PET imaging in a well-established murine cardiac rejection model.
  
  
  METHODS
  Heterotopic transplants were performed using minor major histocompatibility complex-mismatched B6.C-H2 donor hearts in C57BL/6(H-2) recipients. C57BL/6 donor hearts into C57BL/6 recipients served as isograft controls. [F]FDG PET imaging was performed weekly between posttransplant days 7 and 42, and the percent injected dose was computed for each graft. [N]NH3 imaging was performed to evaluate myocardial perfusion.
  
  
  RESULTS
  There was a significant increase in [F]FDG uptake in allografts from day 14 to day 21 (1.6% to 5.2%; P < 0.001) and uptake in allografts was significantly increased on posttransplant days 21 (5.2% vs 0.9%; P = 0.005) and 28 (4.8% vs 0.9%; P = 0.006) compared to isograft controls. Furthermore, [F]FDG uptake correlated with an increase in rejection grade within allografts between days 14 and 28 after transplantation. Finally, the uptake of [N]NH3 was significantly lower relative to the native heart in allografts with chronic vasculopathy compared to isograft controls on day 28 (P = 0.01).
  
  
  CONCLUSIONS
  PET imaging with [F]FDG can be used after transplantation to monitor the evolution of rejection. Decreased uptake of [N]NH3 in rejecting allografts may be reflective of decreased myocardial blood flow. These data suggest that combined [F]FDG and [N]NH3 PET imaging could be used as a noninvasive, quantitative technique for serial monitoring of allograft rejection and has potential application in human transplant recipients.
authors: 1 Transplant Research Program, Boston Children's Hospital. 2 Department of Cardiology, Boston Children's Hospital, Boston, MA. 3 Department of Pediatrics, Harvard Medical School, Boston, MA. 4 Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston Children's Hospital, Boston, MA. 5 Department of Radiology, Harvard Medical School, Boston, MA. 6 Division of Nephrology, Department of Medicine, Boston Children's Hospital, Boston, MA.
authors: Kevin P
authors: KP
authors: Daly
authors: Jason L J
authors: JL
authors: Dearling
authors: Tatsuichiro
authors: T
authors: Seto
authors: Patricia
authors: P
authors: Dunning
authors: Frederic
authors: F
authors: Fahey
authors: Alan B
authors: AB
authors: Packard
authors: David M
authors: DM
authors: Briscoe
mesh_terms: D064591:Allografts; D000641:Ammonia; D000818:Animals; D050528:Diet, Carbohydrate-Restricted; D004195:Disease Models, Animal; D019788:Fluorodeoxyglucose F18; D006084:Graft Rejection / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000276:immunology; D006321:Heart / Q000000981:diagnostic imaging* / Q000187:drug effects; D016027:Heart Transplantation / Q000009:adverse effects*; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008810:Mice, Inbred C57BL; D055414:Myocardial Perfusion Imaging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D013997:Time Factors
chemical_list: D007166:Immunosuppressive Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D000641:Ammonia