3T MR DW和BOLD对移植肾初步研究

目的:研究3.0T MR对移植肾DWI和BOLD成像的可行性.初步设定在3.0T MR上正常自体肾和正常移植肾的ADC值和R2*值范围.对比慢性移植肾病的ADC和R2*值,希望能无创性地加以鉴别.方法:对16例正常人及16例肾移植患者(8例为正常移植肾,8例慢性移植肾病)进行DWI和BOLD功能成像,在工作站上分别进行皮质和髓质ROI的定位,并记录ADC值和R2*值,对所得的结果进行统计学分析.结果:在3.0T MR上肾脏DWI和BOLD图像信噪比良好,能满足成像要求.自体肾和正常移植肾的皮髓质ADC值和R2*值的基线和变化范围均较以前报道的在1.5T上获得的高.慢性移植肾病的皮质ADC值、髓质R2*值及髓皮质R2*比值均较正常移植肾降低,并且有统计学意义.结论:3.0T MR扫描仪对肾脏DWI和BOLD功能成像是可行的,并且有利于对肾脏的功能研究,对慢性移植肾病的鉴别有一定帮助.

Study of Transplanted Kidneys by Diffusion-weighted and BOLD MRI at 3T

Purpose: To evaluate the feasibility of diffusion-weighted(DW) and blood oxygenation level-dependent(BOLD) magnetic resonance imaging(MRI) in patients with renal allograft,and to compared the ADC and R2* values of the cortex and medulla of the transplanted kidneys with the values of the native kidneys of normal healthy volunteers at a 3.0T MR scanner.To preliminarily differentiate chronic allograft nephropathy(CAN) from normal transplanted kidney.Methods: Sixteen patients with normal renal function(n=8) or chronic allograft nephropathy(n=8) and 16 age and gender matched healthy volunteers underwent DWI and BOLD MR imaging at a 3.0T scanner.Circular regions of interest(ROI) were delineated in the renal cortex and medulla on ADC maps and R2* maps on the workstation.The statistical analyses of all the results were performed with software SPSS(version 11.0).Results: The SNRs of transplanted kidney could meet the request of imaging.Baseline and the range of ADC values and R2* values achieved in patients at 3.0T scanner were higher than those at 1.5T scanner before.The cortical ADC(CADC),medullary R2*(MR2*) and medullary to cortical R2* ratios(MCR2*) were significant lower in CAN kidneys than in normal transplanted kidneys.Conclusion: At 3.0T MR scanner,DW and BOLD MRI are feasible and benefit both in native renal and in renal allograft.fMRI can be used to non-invasively evaluate the renal function earlier and help to differentiate from CAN.