ROC曲线分析在肾上腺肿瘤的动态增强CT、MRI检查中的应用

目的 探讨应用受试者操作特性(ROC)曲线评价以肿瘤廓清率为标准利用动态增强CT、MRI检查鉴别肾上腺肿瘤的价值及其这两种检查方法的相关性.资料与方法 25例共28个肾上腺肿瘤均先行平扫及动态增强CT检查,之后再行平扫及动态增强MRI检查,以肿瘤的廓清率为鉴别标准,利用ROC曲线对所选取的诊断标准进行评价,通过ROC曲线下面积(AZ值)来确定所选择诊断标准的价值,并对这两种检查方法行相关性分析.结果 在延迟5～35 min时间点,以肿瘤的廓清率为标准对肾上腺肿瘤的鉴别诊断价值较大(AZ值均在0.7以上),两者之间差异无统计学意义(P＞0.05),再通过对两组变量,即两种检查方法中的廓清率进行分析,认为在延迟5～50 min时,两组变量对肾上腺肿瘤的鉴别诊断均具有高度相关性.结论 以肿瘤的廓清率为诊断标准,无论是利用动态增强CT还是动态增强MRI检查,均可提高肾上腺肿瘤的鉴别诊断水平,两种检查方法对于肾上腺肿瘤的鉴别诊断价值差异无统计学意义,且检查结果具有一致性.

The value of Correlation between Dynamic Contrast-Enhanced CT and MRI in Adrenal Tumors Using Analysis of ROC Curve

Objective To analyze the differential diagnostic value with the threshold of washout rate of enhancement and the correlation between dynamic contrast-Enhanced CT and MRI in adrenal tumors through analysis of ROC curve. Materials and Methods 25 patients with 28 adrenal tumors were enrolled into this study. All these tumors underwent precontrast and dynamic contrast-enhanced CT first, and then underwent precontrast and dynamic contrast-enhanced MRI. The differentiation of adrenal tumors was carried out based on the washout ratio and the value was evaluated and testified by means of ROC system, and then, the differential value of AZ was estimated and the correlation of these kinds of methods was analyzed. Results The threshold of washout rate of enhancement was the most valuable in differentiation adrenal tumors between 5 min and 35 min(the value of AZ was bigger than 0.7), there was no statistical difference between them(P>0.05). There was a highly correlation between the dynamic contrast-enhanced CT and MRI in differentiation adrenal tumors through analysis of two variable quantities. Conclusion There is the correlation between dynamic contrast-enhanced CT and MRI on the basis of washout rate of enhancement in differentiation of adrenal tumors. Furthermore, there is no significant difference in the results of CT and MRI.