Diffusion-weighted Imaging with T2 Mapping for Evaluation of Delayed Renal Function Recovery after Renal Transplantation

Objective: To explore the clinical value of diffusion-weighted imaging (DWI) combined with T2 mapping for the early evaluation of delayed graft function (DGF) after renal transplantation. Method: A total of 92 patients who underwent allogeneic renal transplantation were prospectively recruited. All patients underwent magnetic resonance imaging of the transplanted kidneys after the operation. Diffusion-weighted imaging and mapping of the T2-relaxation time (T2 mapping) were measured and analysed. According to the recovery of renal function within one week after surgery, the patients were divided into a normal graft function (NGF) group and a DGF group. Results: The apparent diffusion coefficient (ADC) values of the cortex and medulla in the DGF group were significantly lower than in the NGF group (P < 0.05). The T2 values of the cortex and medulla in the DGF group were significantly higher than in the NGF group (P < 0.05). The eGFR was positively correlated with the cortical ADC value (P < 0001) and medullary ADC value (P < 0001) and negatively correlated with the medulla T2 value (P = 0.027). The results of the binary logistic regression analysis indicated that age, creatinine level, eGFR, cortical ADC value, medulla ADC value, cortical T2 value and medulla T2 value were independent factors related to DGF. Using these 7 indicators for joint prediction, the AUC was 0.895, and the prediction effect was good. Conclusion: Diffusion-weighted imaging combined with T2 mapping has important differential diagnostic value for DGF after renal transplantation.