双能CT定量参数预测乳腺浸润性导管癌病理分级的价值

目的:探讨双能量CT定量参数在预测乳腺浸润性导管癌病理分级中的价值。方法:搜集2019年7月-2020年3月在本院经病理证实的52例浸润性乳腺癌患者的病例资料。其中乳腺癌病理分级为Ⅱ级者31例,Ⅲ级者21例。所有患者行动脉期和静脉期双能胸部CT增强扫描。将双期增强图像传输至MMWP工作站进行后处理,获得碘图和能谱曲线。在双期碘图上分别选取病灶强化最明显的层面,在病灶及主动脉中心勾画ROI测量碘浓度(IC),记录各ROI的能谱曲线上40~140 keV各单能级水平时的CT值,计算病灶的相对碘浓度(SIC)及能谱曲线的斜率(λ)。采用t检验比较不同病理分级之间双期图像上各项定量参数的差异;采用Spearman秩和检验分析定量参数与乳腺癌病理分级的相关性。结果:动脉期中,Ⅱ级和Ⅲ级组中病灶的IC分别为(1.084±0.365)和(1.690±0.839)mg/mL,SIC分别为0.124±0.616和0.196±0.118,λ值为1.645±0.473和3.029±1.548;静脉期中,Ⅱ级与Ⅲ级组中病灶的IC分别为(1.819±0.696)和(2.271±0.850)mg/mL,SIC值分别为0.307±0.118和0.405±0.192,λ值分别为3.508±0.815和4.112±1.176。动、静脉两期中,两种组织学分级病灶之间IC、SIC和λ值的差异均具有统计学意义(P<0.05)。动脉期病灶的IC、SIC和λ值与乳腺癌组织学分级之间呈弱或中等程度相关(r值分别为0.408、0.357和0.501),ROC曲线下面积(AUC)分别为0.739、0.710和0.794,λ值鉴别Ⅱ级和Ⅲ级乳腺癌的敏感度为81.0%、特异度为67.7%。结论:浸润性乳腺癌的双能CT碘图和能谱曲线的相关定量参数与组织学分化程度之间具有一定相关性,双能CT定量参数能为不同分化程度的浸润性乳腺癌的鉴别诊断提供定量分析手段。

The value of dual-energy CT quantitative parameters in predicting the pathological grade of breast invasive ductal carcinoma

Objective:The purpose of this study was to explore the predictive value of dual-energy CT quantitative parameters in the pathological grade of breast invasive ductal carcinoma(IDC).Methods:The clinical data of fifty-two patients with breast IDC confirmed by pathology from July 2019 to March 2020 in our hospital were collected.There were 31 cases with pathologic grade-Ⅱand 21 cases with grade-Ⅲ.All patients underwent dual phase(arterial and venous phase)contrast-enhanced chest dual-energy CT scan.The iodine map and the energy spectrum curve(ESC)were obtained by transmitting the dual-energy CT images of arterial and venous phase to the MMWP post-processing workstation.The ROI was placed at the markedly enhanced areas in each lesion and at the center of the aorta on the same slice,then the iodine concentration was measured;and according to the energy spectrum curve,the CT values of the lesions and aorta at each monochromatic level in 40~140keV in the two phase were recorded,and the relative iodine concentration(SIC)of the lesion and the slope of the ESC(λ)were calculated.The independent t-test was used to compare the quantitative parameters of the two groups(grade-Ⅱand grade-Ⅲ),and the Spearman rank sum test was used to analyze the correlation between quantitative parameters and the pathologic grade of breast IDC,and the ROC curve was used to analyze the diagnostic efficacy of the quantitative parameters.Results:On the arterial phase,ICs in grade-Ⅱand grade-Ⅲgroups were(1.084±0.365)and(1.690±0.839)mg/mL,SICs were 0.124±0.616 and 0.196±0.118,andλvalues were 1.645±0.473 and 3.029±1.548;On the venous phase,ICs in grade-Ⅱand grade-Ⅲgroups were(1.819±0.696)and(2.271±0.850)mg/mL,SICs were 0.307±0.118 and 0.405±0.192,andλvalues were 3.508±0.815 and 4.112±1.176.The differences of IC,SIC,andλvalues between the two groups were statistically significant on both arterial and venous phases(all P<0.05).The IC,SIC,andλvalues on arterial phase were weakly or moderately correlated with the histological grade of breast cancer with r values of 0.408,0.357 and 0.501.The area under the ROC curve(AUC)of IC,SIC andλon the arterial phase for differentiating the two grades were 0.739,0.710 and 0.794,respectively.The AUC of theλwas the largest,with sensitivity of 81.0%and specificity of 67.7%.Conclusion:The quantitative parameters of the energy spectrum curve and iodine map on dual-energy CT are correlated with the pathologic grade of infiltrative breast cancer,providing a quantitative analysis tool for the prediction of differentiation degree of invasive breast cancer.