血氧水平依赖的磁共振成像对早期移植肾排异的诊断和预测作用

目的 探讨血氧水平依赖的功能磁共振成像（BOLD-MRI）在早期移植肾排异中的诊断和预测作用。 方法 纳入2005年12月至2007年3月在浙江大学医学院附属第一医院肾脏病中心首次接受同种异体尸体肾移植患者共103例，分为肾功能正常组82例，急性排异组（病理证实）21例，记录两组的基线资料并测量移植肾皮、髓质磁共振参数R2*。 结果 急性排异组髓质R2*（MR2*）值显著低于肾功能正常组[（14.02±2.68）/s比（16.66±2.82）/s，P < 0.01]；ROC曲线分析显示MR2*值可作为急性排异的辅助诊断指标；肾功能正常组中低水平MR2*值（MR2*<14.9/s，23例）者日后发生急性排异的比例高于高水平MR2*值（MR2*≥14.9/s，59例）者，但差异无统计学意义（17.39％ 比 8.47％，P ＝ 0.259）。 结论 移植肾MR2*值可以作为肾移植术后早期急性排异的辅助诊断指标，并且可能有一定的预测价值。

Diagnosis and prediction of early acute renal transplant rejection with blood oxygen level dependent magnetic resonance imaging

Objective To assess the value of blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI)in diagnosis and prediction of early acute renal transplant rejection.Methods BOLD-MRI was performed in a cohort of 103 patients undergoing cadaver renal transplantation between Dec 2005 and March 2007.Among them,82 recipients had nomlal renal function,21 had biopsy-proved acute rejection.R2* (1/s)measurements were obtained in the medulla and cortex of grafted kidneys. Results R2* values of the medulla were significantly lower in the acute rejection group[R2*=(14.02±2.68)/s]than that in the normally functioning transplants group [R2*=(16.66+2.82)/s],the difference between these two groups was significant (P＜0.01);ROC curve analyses suggested that medullary MR2* values could accurately identify acute rejection in the early post-transplantation period.In the normal functioning transplant group,those with lower medullary R2* values (MR2*＜14.9/s,n=23) had higher acute rejection rates than those with higher medullary R2* values (MR2*＞14.9/s,n=59) in the first 6 months following transplantation,but the difference between these two groups was not significant (17.39% vs 8.47%,P=0.259). Conclusions Mean R2* values in the medullary regions of grafted kidneys with BOLD-MPd may be a non-invasive diadynamic criteria with good sensitivity and specificity,and may be a valuable predictor of early acute renal transplant rejection.