Role of elastography and dynamic contrast-enhanced ultrasound in the evaluation of pancreas transplantation rejection
摘要
Rejection is the leading cause of graft failure, and its diagnosis remains a challenge. Elastography and dynamic contrast-enhanced ultrasound (DCE-US) are novel non-invasive techniques for quantifying tissue elasticity and perfusion. Their role in pancreas graft rejection has not yet been defined.
Materials and methodsFrom October 16 to January 20, all pancreas transplantations performed at our institution were prospectively studied with elastography and DCE-US at 1 week, 3 weeks, and 12 months post-transplantation. Surveillance biopsies were performed at 3 weeks and 12 months. Elastography and DCE-US were also conducted in all requested biopsies during this period (regardless of the date of transplantation). Patients were categorized according to the biopsy result: normal/rejection. Grafts with other complications were excluded. Cut-off values were established.
ResultsOne hundred twenty-one elastography and 127 DCE-US in 56 patients were included. All parameters showed a high dispersion during the first 90 days post-transplantation. After this period, the rejection group presented higher stiffness (0.97 vs 1.46 m/s, p < 0.001) and lower perfusion. The optimal cut-off value for elastography was 1.27 m/s (AUC 0.80), and for DCE-US were: peak enhancement 601 a.u. (AUC 0.67), wash-in AUC 2748 a.u. (AUC 0.70), wash-in rate 118 a.u. (AUC 0.65), wash-in perfusion index 369 a.u. (AUC 0.67), wash-out AUC 5181 a.u. (AUC 0.69) and total AUC 6388 a.u. (AUC 0.68). A combined predictive score showed that alteration of elastography and DCE-US was associated with a 23.2-fold probability of rejection.
ConclusionAfter the first 90 days post-transplantation, pancreas graft rejection is associated with higher stiffness and lower graft perfusion.
Key Points