Monitoring the renal allograft function at an early stage after transplantation is important to ensure a successful outcome of renal transplantation [1]. In this study, we performed IVIM, ASL and T1 mapping to assess the renal allografts function at an early stage after transplantation, and compared the diagnostic value of the derived MR parameters in renal allografts function evaluation.This prospective study was approved by the local ethics committee, and written informed consent was obtained from all participants. A total of 82 participants, including 62 renal allograft recipients (2-4 weeks after kidney transplantation) and 20 volunteers received MR imaging on a 3T MR scanner (MAGNETOM Trio, a Tim system, Siemens Healthcare, Erlangen, Germany). Recipients were divided into two groups with good or impaired renal function according to the estimated glomerular filtration rate (eGFR) with a threshold of 60 ml/min/1.73m2. IVIM was acquired using a prototype single-shot echo planar imaging (ss-EPI) sequence with 11 b values of 0, 10, 20, 40, 60, 100, 150, 200, 300, 500 and 700 s/mm2 on 3 gradient directions, and a full bi-exponential fitting was used to calculate ADCslow, ADCfast and PF and a single-exponential fitting was used to calculate ADC. ASL was performed using a prototype flow-sensitive alternating inversion recovery (FAIR) TrueFISP sequence with a TI of 1200 ms for perfusion images and a TI of 4000 ms for M0 image. T1 mapping was also acquired using a modified look-locker inversion-recovery (MOLLI) sequence. Cortical ADC, ADCslow, ADCfast, PF, RBF and T1 values were compared among three groups by one-way ANOVA with Bonferroni post-test. The correlation of ADC, ADCslow, ADCfast, PF, RBF and T1 values with eGFR in recipients was evaluated using Pearson correlation analysis. Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic efficacy of each parameter to discriminate allografts with impaired function from good function. P <0.05 was considered statistically significant.In allografts with good function cortical ADC, ADCslow, ADCfast, PF showed no significant difference compared with healthy controls(P >0.05), but cortical RBF was lower than healthy controls(P <0.001), and cortical T1 values were higher than healthy controls(P <0.001).Cortical ADC, ADCslow, ADCfast, PF and RBF were lower for allografts with impaired function than with good function, and T1 values were higher for allografts with impaired function than with good function (P <0.05; Figure 1). Cortical ADC, ADCslow, ADCfast, PF and RBF had a significant positive correlation with eGFR, and T1 values had a significant negative correlation with eGFR (P <0.01 for all; Figure 2). Comparing the diagnostic value of each parameter, cortical ADC and RBF showed a higher area under the ROC curve (AUC) (0.81 and 0.77 respectively) than ADCslow, ADCfast, PF and T1 values (0.72, 0.66, 0.72 and 0.68 respectively), but without significant difference (P>0.05; Figure 3).Multiparametric MR imaging can provide valuable information of renal allograft function at an early stage after kidney transplantation. Both diffusion and perfusion were decreased in renal allografts with impaired function. ADC derived from IVIM and RBF derived from ASL showed a higher diagnostic efficacy to discriminate between allografts with impaired function and allografts with good function.