肾透明细胞癌扩散峰度成像与病理学相关性研究

The correlation between diffusion kurtosis imaging and pathological condition in clear cell renal carcinoma

目的探讨扩散峰度成像(diffusion kurtosis,DKI)的平均扩散值(mean diffusion,MD)、平均峰度值(mean kurtosis,MK)在评价肾透明细胞癌微血管密度(microvessel density,MVD)、微血管区(microvessel area,MVA)和Ki-67的价值。材料与方法回顾性分析肾透明细胞癌33例患者,行MRI常规序列和DKI检查,比较不同核分级的MD、MK、MVD、MVA和Ki-67值,进行统计学分析。结果肾透明细胞癌低、高核分级的MD值分别为(2.43±0.11)×10^(-3)mm^(2)/s和(2.22±0.07)×10^(-3)mm^(2)/s。MK值分别为0.73±0.03和0.82±0.04,MK值优于MD。不同核分级之间MVD、MVA和Ki-67值比较差异有统计学意义(t值分别为-8.23、-15.47、和-7.84,P<0.05)。MD值与MVD、MVA和Ki-67值分别存在显著的负相关(r值分别为-0.710、-0.746和-0.733,P<0.05)。MK值与MVD、MVA和Ki-67值分别存在显著的正相关(r值分别为0.787、0.772、和0.801,P<0.05)。结论DKI可用于无创性评价肾透明细胞癌的病理状态(MVD、MVA和Ki-67值)。

Objective:To investigate if the mean diffusivity(MD)and mean kurtosis(MK)allows assessment of pathological condition of clear cell renal cell carcinoma(CCRCC),including microvessel density(MVD),microvessel area(MVA),and Ki-67.Materials and Methods:Thirty-three patients were enrolled in this study,with CCRCC confirmed by surgical pathology.For diffusion kurtosis imaging(DKI),a coronal echo planar imaging(EPI)sequence was performed(repetition time:4000 ms;echo time:99 ms;diffusion direction:3;number of acquisitions:4;b=0,800,and 1600 s/mm^(2);and slice thickness:4 mm with no intersection gap).MD,MK,MVD,MVA,and Ki-67 were compared between the different nuclear grades.Correlations between MVD,MVA,and Ki-67 and DKI parameters were evaluated.Results:The MDs of low grade and high grade CCRCCs were(2.43±0.11)×10^(-3)mm^(2)/s and(2.22±0.07)×10^(-3)mm^(2)/s,respectively.The MK was 0.73±0.03 and 0.82±0.04,respectively.MK were better than MD values in identifying the grade of nuclear grade.A significant difference between high and low grade in MVD,MVA,and Ki-67 was found(t=-8.23,-15.47,and-7.84,respectively,P<0.05).Significant negative correlations between the MD value and MVD,MVA,and Ki-67 were observed(r=-0.710,-0.746,and-0.733,respectively,P<0.05).Significant positive correlations between the MK value and MVD,MVA,and Ki-67 were observed(r=0.787,0.772,and 0.801,respectively,P<0.05).Conclusions:DKI can be used to noninvasively assess MVD,MVA,and Ki-67 of CCRCC.