The value of arterial spin labeling MRI for evaluating early renal allograft function / 中华放射学杂志

ABSTRACT

Objective To assess the value of arterial spin labeling(ASL) MRI in the staging of early renal allograft function. Methods Sixty two renal allograft recipients (2 to 4 weeks after kidney transplantation) and 20 age match volunteers were included in this study. All subjects underwent conventional MRI and ASL MRI which was performed in the oblique-sagittal plane. Recipients were divided into two groups according to the estimated glomerular filtration rate (eGFR), recipients with good allograft function (eGFR≥60 ml · min-1 · 1.73 m-2,n=37) and recipients with impaired allograft function (eGFR<60 ml · min - 1 · 1.73 m - 2,n=25). Renal blood flow (RBF) was measured and an intra-class correlation coefficient (ICC) was calculated to confirm the reproducibility of the measured results from two doctors. One-way analysis of variance (ANOVA) and Bonferroni were used to compare the different cortical RBF among three groups. Correlation of RBF with eGFR was evaluated using Pearson correlation coefficients. The receiver operating characteristic (ROC) curve was performed to assess the diagnostic efficacy of using cortical RBF to discriminate allografts with impaired function from good function. Results RBF values showed good reproducibility between doctors with an ICC larger than 0.90 in different group. Mean cortical RBF were (390 ± 61),(290 ± 69),(201 ± 86) ml · 100 g-1 · min-1 for healthy controls, recipients with good and impaired allograft function, respectively(F=37.313,P<0.01). RBF exhibited a significant correlation with renal function as determined by eGFR for recipients (r=0.60,P<0.01). Mean cortical RBF showed a high area under the ROC curve (0.773) to discriminate renal allografts with different function, with a sensitivity of 56.0% (14/25) and a specificity of 89.2% (33/37). Conclusion ASL MRI can assess the early renal allografts perfusion, and provide valuable information in the staging of renal function. It could be a useful method for evaluating renal function noninvasively.