Background: Transplant arteriosclerosis is still the leading cause of late mortality after heart transplantation despite advances in immunosuppression regimes. Experimental mouse models have substantially contributed to a better understanding of the multifactorial pathogenesis, but the major limitation of these studies is the difficulty in monitoring progression of transplant arteriosclerosis over time. Therefore, the aim of this study was to investigate whether MR measurements are sensitive enough to detect characteristic vascular lesions in a small animal transplantation model.
Methods: For this purpose we investigated 22 iso- and allogeneic aortic graft transplanted mice in vivo with a 4.7 T MR scanner using a 2D-RARE technique, 3D time-of-flight angiography and 3D phase contrast angiography as well as a special snake-based reconstruction algorithm. The MR lumen values of patency from native images and from 3D vessel reconstructions of the respective methods were correlated with conventional histological analysis.
Results: A comparison of the different techniques showed that angiographic MR modalities correlated well with histological measurements. 2D-RARE sequences were inferior to the sequences obtained by other ones. Superior correlations and the most accurate results were found for vessel reconstruction based on 3D angiographic time-of-flight data.
Conclusion: These data demonstrate that mouse in vivo MR imaging is sensitive enough to detect and quantify vascular changes caused by transplant arteriosclerosis.
© Georg Thieme Verlag KG Stuttgart · New York.