单、双指数模型扩散加权成像对非小细胞肺癌Ki-67表达的预测价值

Intravoxel incoherent motion diffusion weighted imaging as an imaging biomarker to predict the Ki-67 expression in non-small cell lung cancer patients

目的评估双指数扩散模型体素内不相干运动扩散加权成像(intravoxel incoherent motion diffusion weighted imaging,IVIM)各参数(灌注分数、假扩散系数及真扩散系数)及单指数扩散模型扩散加权成像(diffusion weighted imaging,DWI)表观扩散系数(apparent diffusion coefficient,ADC)对非小细胞肺癌Ki-67表达的预测价值。材料与方法共60例患者(41例男性,19例女性,年龄35～81岁)使用3.0 T MR扫描仪行IVIM (b=0、50、100、150、200、400、600、800 s/mm2)、DWI (b=50、800 s/mm2)检查。所有患者均通过外科手术或CT引导下穿刺活检或支气管镜检查获得病理结果。使用body diffusion toolbox软件测量ADC、D、f and D*值,2名有经验的放射科医师分别对各参数值进行测量,每个病灶测量三次取平均值。使用组内相关系数(the intraclass correlation coefficient,ICC)计算2名医师测量各参数的一致性,进而使用Spearman相关计算ADC,D,f and D*值与Ki-67的相关性。结果 ADC及D值与Ki-67呈负相关关系(ADC:r=-0.335,P=0.009)(D:r=-0.330,P=0.01),f、D*值与Ki-67无显著相关关系;肺腺癌ADC值与Ki-67呈负相关关系(r=-0.424,P=0.008)。结论单指数扩散模型参数ADC、双指数扩散模型参数D值有望成为无创性的在体预测非小细胞肺癌Ki-67表达程度的指标,这为使用影像学方法预测非小细胞肺癌的预后提供客观依据。

Objective:To evaluate the capacity of noninvasive intravoxel incoherent motion diffusion weighted imaging(IVIM)parameters(perfusion fraction(f),pseudo diffusion coefficient(D^*),true diffusion coefficient(D)and apparent diffusion coefficient(ADC)value in preoperative predicting the Ki-67 expression in non-small cell lung cancer.Materials and Methods:The institutional review board approved this study,and written informed consent was obtained from each patient.The IVIM(b=0,50,100,150,200,400,600,800 s/mm^2)and diffusion weighted imaging(DWI,b=50,800 s/mm^2)were used to examine 60 patients(41 males,19 females,35-81 years old)with a 3.0 T scanner.All patients had received a histopathologic diagnosis of lung cancer based on bronchoscopy,percutaneous needle-guided,or surgical biopsies,all of them had undergone immunohistochemistry staining.ADC,D,f and D^*were generated by using a prototype software body diffusion toolbox,two radiologists drew the region of interest on the parametric maps.The areas of focal necrosis,large vessels,and prominent artifacts were avoided carefully.Each lesion was measured for three times.The correlation between ADC,D,D^*,f value and Ki-67 expression is calculated by Spearman correlation.Results:The ADC and D value of non-small cell lung cancer was negatively correlated with the Ki-67 expression(ADC value:r=-0.335,P=0.009)(D:r=-0.330,P=0.01).The ADC value of lung adenocarcinoma was negatively correlated with the Ki-67 expression(r=-0.424,P=0.008).Conclusions:The ADC and D value would be an imaging biomarker for the prediction of tumor aggressiveness indicators such as Ki-67 in non-small cell lung cancer.