ROC分析在多层螺旋CT综合性诊断孤立性肺结节良恶性中的应用

Role of ROC analysis in comprehensive diagnosis to differentiate malignant from benign solitary pulmonary nodules with multi-slice spiral CT

目的探讨在孤立性肺结节(SPN)良恶性的多层螺旋CT(MSCT)综合性诊断中ROC分析的应用价值。方法经手术和/或穿刺活检组织病理结果证实的SPN 177个,由3位资深的CT诊断医师分别对每个SPN的MSCT图像进行全面分析,依其影像特征进行综合评分,根据SPN的最大径(D),以MSCT评分为分类值,分别绘制D≤3.0 cm、2.0 cm<D≤3.0 cm和D≤2.0 cm SPN良恶性诊断的ROC曲线,用Z检验对ROC曲线下面积(AZ)进行统计学分析。结果 MSCT评价SPN良恶性的ROC曲线下面积分别为0.879±0.030、0.899±0.039和0.867±0.044,经检验差异有统计学意义(P<0.05),其最佳阈值分别为3.0、3.5和2.5。结论 ROC分析在综合运用MSCT提供的影像信息全面评价SPN的良恶性方面具有显著应用价值,将MSCT评价SPN的结果与恶性概率相结合,能为患者提供合理的处理方案。

Objective To study the role of receiver operating characteristic（ROC） analysis in comprehensive diagnosis to differentiate malignant from benign solitary pulmonary nodules（SPNs） with multi-slice spiral computed tomography（MSCT）.Methods 177 SPNs were examined with MSCT and pathologically confirmed by surgery and/or needle biopsy.All MSCT images were assessed and graded by three senior radiologists on the basis of malignant likelihood of morphological and density characteristics.According to the maximum diameter（D）,ROC curves were constructed and optimal thresholds were determined for diagnosis of malignancy in SPNS of D≤3.0 cm,2.0 cmD≤3.0 cm and D≤2.0 cm.ROC analysis was used to evaluate the efficiency of MSCT in differentiating malignant from benign SPNs.The area under the ROC curve（Az） was used as an index for diagnostic efficiency with MSCT.Az values were statistically analyzed by Z-test.Results Az values of ROC curves were 0.879±0.030 in SPNs of D≤3.0 cm,0.899±0.039 in SPNs of 2.0 cmD≤3.0 cm and 0.867±0.044 in SPNs of D≤2.0 cm.The differences were statistically significant according to the Z-test（P0.05）.The three optimal thresholds for diagnosis of malignancy were 3.0,3.5 and 2.5.Conclusion Application of ROC analysis is of obvious value in the differential diagnosis of SPNs with comprehensive imaging characteristics obtained by MSCT.It is favorable to combine the diagnosis of SPNs by MSCT with the malignant probability and to improve the treatment of SPNs in clinical practice.