SP777EARLY RENAL PERFUSION IMPAIRMENT QUANTIFIED FUNCTIONAL MRI IS PREDICTIVE FOR DELAYED RENAL GRAFT FUNCTION AND RENAL OUTCOME ONE YEAR AFTER KIDNEY TRANSPLANTATION

Abstract

Introduction and Aims: Delayed graft function (DGF) after kidney transplantation is a frequent problem, which is associated with an increased risk of acute rejection, impaired long‐term allograft function and graft loss. In this study, we use functional magnetic resonance imaging (MRI) to investigate renal perfusion changes in patients early after kidney transplantation compared to renal function and allograft histology after biopsy. Methods: Forty‐six patients underwent functional MRI 4 to 11 days after kidney transplantation on a 1.5 Tesla MRI scanner. Contrast‐freeMRI renal perfusion images were acquired using an arterial spin labelling technique. Renal function was assessed daily early after transplantation and until one year follow‐up by glomerular filtration rate (eGFR) and was correlated with renal perfusion. DGF was defined as lack of s‐creatinine decrease by 10% daily on three consecutive days or need for dialysis treatments during the first week after transplantation. Renal biopsy was performed within 5 days ofMRI and assessed for renal morphology, signs of rejection and acute tubular injury. Values are given as mean±SEM. Results: 26/46 patients had a DGF of which 9 patients had an acute rejection including Borderline changes and 8 had other changes such as tubular injury or glomerulosclerosis. Renal perfusion was significantly lower (231±15 ml/(min∗100g)) in the DGF group compared to the group with initial allograft function (331±15 ml/(min∗100g), p<0.001). Living donor allografts exhibited higher perfusion values compared to deceased donor allografts (339±19 vs. 243±14 ml/(min∗100g), p<0.001). Renal perfusion significantly correlated with eGFR (r=0.64, p<0.001), number of dialyses sessions (r=‐0.63, p<0.001), and cold ischemia time (r=‐0.48, p<0.01). In the subgroup of DGF patients with better renal function after one year (eGFR ≥30 ml/min) renal perfusion shortly after transplantation was significantly higher (260±21 ml/(min∗100g)) than in DGF patients with persistent severe impairment of renal function (eGFR <30 ml/min) or graft loss (162±26 ml/(min∗100g), p<0.01). Conclusions: Non‐invasive functional MRI allows quantification of renal perfusion impairment early after kidney transplantation in patientswithDGF and predicts further renal graft outcome after one year. (Figure Presented).