容积ADC直方图对胆囊癌的诊断价值

Volumetric Apparent Diffusion Coefficient Histogram Analysis on Gallbladder Carcinoma

目的探讨弥散加权成像所得的容积表观扩散系数(ADC)直方图对胆囊癌的诊断价值。方法收集华中科技大学同济医学院附属同济医院2017年9月~2018年12月确诊并有完整MRI资料的胆囊病变患者86例,由2位医师分别测量患者术前进行的DWI检查,生成全容积ADC值灰度直方图,计算出胆囊病变的灰度平均值、第10百分位数、第25百分位数、第50百分位数、第75百分位数、第90百分位数、标准差、峰度、偏度、熵。对2位医师的测量结果采用Weighted K检验评估一致性。用曼-惠特尼U检验对比良、恶性两组病变各参数差异的显著性,并根据受试者操作特性曲线(ROC)下面积(AUC)判断其诊断准确性,评价容积ADC直方图参数对于胆囊良、恶性病变的鉴别诊断效能。结果(1)一致性分析:2名医师的测量数据一致性分析具有较好的可信度,Kappa值为0.715~0.872。(2)胆囊癌的ADC灰度平均值、第10百分位数、第25百分位数、第50百分位数、第75百分位数、第90百分位数均低于胆囊良性病变(均P<0.01)。(3)胆囊恶性病变的ADC值标准差和熵显著高于良性病变(均P<0.05),但是良恶性病变间的峰度和偏度没有显著差异(均P>0.05)。(4)ADC的平均值、第10百分位数、第25百分位数、第50百分位数、第75百分位数、第90百分位数、标准差、峰度、偏度和熵在ROC曲线上对应的AUC分别为0.856、0.963、0.959、0.942、0.908、0.721、0.861、0.526、0.513和0.612。第10百分位数具有较高的鉴别诊断效能,其AUC范围为0.959~0.968。当临界值为95×10^-5mm^2/s时具有最大的约登指数,其特异度、准确度分别为89.5%、95.4%。结论ADC容积定量直方图可以对胆囊良恶性病变鉴别诊断提供帮助,直方图参数在胆囊癌诊断中具有较大价值。

Objective To evaluate the diagnostic performance of histogram analysis of apparent diffusion coefficient(ADC)derived from diffusion-weighted imaging(DWI)for gallbladder cancer.Methods Our study collected 86 patients with gallbladder disease who had undergone DWI scan for preoperative evaluation in Tongji Hospital from Septemper 2017 to December 2018.Preoperative DWI images of 86 patients with gallbladder disease confirmed by surgery or puncture pathology were measured by two radiologists.Volumetric ADC maps were generated using all slices of the DWI images to obtain histogram parameters,including mean,median,10 th percentile,25 th percentile,75 th percentile,90 th percentile ADC,and SD ADC values,as well as skewness,kurtosis,and entropy.The weighted-K test was used to examine the consistency of the results measured by the two radiologists.Comparisons of these parameters were made by Mann-Whitney U test.The sensitivity and specificity were calculated according to the area under the ROC curve(AUC)to evaluate the differential diagnosis on malignant and benign gallbladder diseases.Results(1)The consistency analysis of the measurement data had good credibility with Kappa values ranging from 0.715 to 0.872.(2)Mean ADC,10 th,25 th,75 th and 90 th percentile ADC of gallbladder cancer were significantly lower than those of benign diseases(P<0.01).(3)SD and entropy of gallbladder cancer were higher than those of benign disease,but there were no significant differences in kurtosis and skewness among these gallbladder diseases.(4)The AUC of the parameters,including ADC mean,10 th percentile,25 th percentile,50 th percentile,75 th percentile,90 th percentile,standard deviation,kurtosis,skewness,entropy were 0.856,0.963,0.959,0.942,0.908,0.721、0.861,0.526,0.513,0.612,respectively.The 10 th percentile yielded the highest AUC that ranged from 0.959 to 0.968.It had the largest Yoden index when the critical value was 95×10^-5mm^2/s,and its specificity and accuracy were 89.5%and 95.4%,respectively.Conclusion Volumetric apparent diffusion coefficient histogram analysis can be helpful for diagnosing gallbladder cancer.