DWI对宫颈癌的诊断及与肿瘤细胞密度相关性的初步研究

A preliminary study of correlation between DWI and the cellularity density in cervical carcinomas

目的初步探讨磁共振扩散成像(DWI)对宫颈癌的诊断价值,分析表观扩散系数(ADC)与肿瘤病理级别及细胞密度相关性。方法分析15例正常宫颈及35例经病理证实的宫颈癌病例常规MRI与DWI图像,观察b值取0、1000s/mm2时其DWI表现及ADC值差异,并进行受试者工作特征曲线(ROC)分析,选取宫颈癌的ADC诊断阈值;对其中30个手术切除的肿瘤行光镜下细胞密度计数,分析其与ADC值相关性。采用SPSS13.0统计软件包完成统计学分析。结果 DWI原始图上宫颈癌信号明显高于正常宫颈,正常宫颈及宫颈癌平均ADC值分别为(1.59±0.25)×10-3mm2/s及(0.97±0.18)×10-3mm2/s(P<0.05),宫颈鳞癌及腺癌平均ADC值分别为(0.80±0.11)×10-3mm2/s及(0.99±0.24)×10-3mm2/s(P<0.05),以上差异均有统计学意义。以ADC值小于1.26×10-3mm2/s为阈值,诊断宫颈癌的特异度为93.33%,敏感度为94.29%,准确率为94.00%;ADC值与肿瘤病理级别及细胞密度均呈负相关(r=-0.697,P=0.000;r=-0.766,P=0.000)。结论 DWI能够鉴别宫颈癌与正常宫颈,定量分析ADC值在一定程度上有助于评估宫颈癌的病理类型及分级,是常规MRI的有益补充。

Objective To investigate the diagnostic value of uterine cervix cancer using diffusion weighted imaging（DWI）,and analyze the correlation between apparent diffusion coefficient（ADC） value and the grades of tumor and also the correlation between ADC value and the cellularity density.Methods Conventional and DWI（diffusion factor of 0 and 1000s/mm2） images of 15 heath volunteers and 35 patients of uterine cervix cancer proved pathologically were reviewed.The DWI appearances of tumors and normal uterine cervix were observed,and the ADC values of them were compared.In order to determine the optimal ADC threshold value to diagnosis and difference for uterine cervix cancer,the ROC curve was analyzed.For 30 tumors after operation,tumor cellularity was counted by mean of optical microscopy,and the correlation was analyzed between the ADC value and the cellularity density.Results All lesions of uterine cervix cancer demonstrate high signal intensity,which was significantly higher than those of the 15 normal uterine cervix.There was significant difference between the mean ADC value of normal uterine cervix（[1.59±0.25]＊10-3mm2/s） and that of uterine cervix cancer（[0.97±0.18]＊10-3mm2/s,P0.05）.In addition,there were statistic differences between squamous carcinoma（[0.80±0.11]＊10-3 mm2/s） and adenocarcinoma（[0.99±0.24]＊10-3mm2/s） of the uterine cervix（P0.05）.When ADC1.26＊10-3mm2/s was used to diagnose uterine cervix cancer,the specificity,sensitivity and accuracy was 93.33%,94.29% and 94.00% respectively.There is negative correlation between ADC value of uterine cervix cancer and the grades of tumor（r=-0.697,P=0.000）,also the ADC value of uterine cervix cancer correlates negatively with the cellularity density（r=-0.766,P=0.000）.Conclusion DWI is a useful supplement for conventional MRI examinationL？which can distinguish uterine cervical carcinoma from normal uterine cervix,and ADC value may help to differentiate the pathological type and grade.