Onset and maintenance of angiogenesis in biomaterials: in vivo assessment by dynamic contrast-enhanced MRI.

Objective: To describe dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as a practical tool for longitudinal assessment of angiogenesis in biomaterials. Background: There is a lack of suitable methods for in vivo evaluation of the integration of biomaterials in a clinical setting. In oncology, DCE-MRI is used for the longitudinal monitoring of altered tumor angiogenesis during therapy. Thus, we investigated whether DCE-MRI enables to assess the integration of biomaterials over time. Methods: The tested material was bovine bone matrix applied in a bilateral sinus lift procedure in combination with concentrated mononuclear cells, including mesenchymal stem cells and autologous thrombin. To assess the development of new blood vessels inside the biomaterial, DCE-MRI was carried out before and 11, 25, 53, and 104 days after surgery. Perfusionparameters were calculated according to the model of Tofts. Results: Analysis of the data revealed increasing parameters for perfusion and blood supply within the transplant over time. It was possible to determine the values for each transplantation site and each point of time separately. Conclusion: DCE-MRI is appropriate to repetitively survey angiogenesis and integration of biomaterials in patients. It seems appropriate as a valuable indicator of treatment response or failure, with consecutive adaption of the therapy regime.