磁共振扩散峰度成像在人体肾脏的应用

摘要

Objective:To investigate the feasibility of magnetic resonance diffusion kurtosis imaging (DKI) applies on human kidneys.Materials and Methods:Thirty healthy male volunteers were recruited in our hospital from March 2016 to February 2017.The MR examination was performed in the coronal plane with a 3.0 T MR scanner.The scanning sequences included T1WI, T2WI and DKI.The DKI sequence used three different b values (0, 500 s/mm2, 1000 s/mm2) and 30 diffusion-sensitive gradient directions.The paired-samples t test was used to compare the DKI parameters of the renal cortex and medulla.The correlated between all parameters with estimated glomerular filtration rate (eGFR) were calculated.Results:The mean kurtosis (MK), axial kurtosis (Ka) and radial kurtosis (Kr) values in renal cortex were greater than those in renal medulla (P＜0.05).The fractional anisotropy (FA) and axial diffusion (Da) values of renal cortex were significantly lower than those of renal medulla (P＜0.05), while the mean diffusion (MD) and radial diffusion (Dr) values of renal cortex were greater than those of renal medulla (P＜0.05).Conclusions:DKI is feasible in human kidney.It can reflect the water molecule diffusion differences between the renal cortex and medulla.Furthermore, its unique kurtosis parameters can also provide microstructure information on renal cortex and medulla.%目的 探讨磁共振扩散峰度成像 (diffusion kurtosis imaging, DKI) 在人体肾脏应用的可行性.材料与方法 收集2016年3月至2017年2月在我院招募的健康男性志愿者35例, 最终纳入30例.采用3.0 T MR进行双侧肾脏冠状位扫描, 扫描序列包括:T1WI、T2WI与DKI序列;DKI采用三个不同b值 (0、500 s/mm2、1000 s/mm2) 和30个扩散敏感梯度方向.采用配对t检验对肾皮质、髓质DKI参数进行组间比较.结果 正常人左、右两侧肾皮质、髓质DKI均无统计学差异 (P＞0.05) .正常人肾脏皮质峰度参数值MK值、Ka值及Kr值均高于髓质 (P＜0.05);皮质的扩散参数FA值、Da值明显低于髓质, MD值、Dr值高于髓质 (P＜0.05) .结论 肾脏的DKI成像不仅能够反映肾皮质、髓质水分子扩散状态差异, 而且其特有的峰度参数值还能够提供更多关于肾皮质、髓质微结构的信息.