运用ROC曲线评价能谱CT碘基物质对鼻咽癌的诊断价值

Evaluation of diagnostic value of iodine base material of energy spectrum CT for nasopharyngeal carcinoma by application of ROC curve

摘要:

目的运用受试者工作特征曲线（receiver operating characteristic curve，ROC曲线）探讨能谱CT碘基物质对鼻咽癌的诊断价值。方法选取经鼻咽活检病理证实的140例鼻咽部病变患者（其中60例鼻咽癌为实验组，80例鼻咽炎症为对照组）。采用能谱CT对所有患者进行GSI增强扫描，测量并计算鼻咽部病变组织的动脉期及静脉期标准化碘浓度比（NIC），对NIC进行组间比较；应用受试者工作特征（ROC）曲线，确定动脉期及静脉期NIC的最佳诊断界点，并以病理诊断为金标准，比较动脉期、静脉期和联合动-静脉期NIC对鼻咽癌的诊断价值。结果实验组动脉期及静脉期NIC与对照组比较有显著性差异（均P<0.01）；动脉期及静脉期NIC的曲线下面积分别为0.902、0.901，对ROC曲线进行分析，确定动脉期及静脉期NIC的最佳诊断界点分别为0.124、0.229；动脉期、静脉期和联合动-静脉期NIC的最佳诊断界点诊断鼻咽癌的灵敏度分别为88.33%、90%、83.33%、特异度分别为83.75%、85%、90%。结论动脉期、静脉期及联合动-静脉期NIC在鼻咽癌诊断中有较高的应用价值，可作为能谱CT诊断鼻咽癌的有效指标。

关键词:鼻咽癌|标准化碘浓度比|ROC曲线|诊断价值

Abstract:

ObjectiveTo explore the diagnostic value of iodine base material of energy spectrum CT for nasopharyngeal carcinoma (NPC) by receiver operating characteristic curve (ROC curve).Methods140 cases with pathologically confirmed nasopharyngeal lesions were included. Of them, 60 cases suffering from nasopharyngeal carcinoma (NPC) were chosen as experimental group, while 80 cases of nasopharyngitis as control. GSI enhanced scan was performed in all patients using energy spectrum CT. The normalized iodine concentrations (NIC) of all lesions on both arterial and venous phases were measured and calculated, and the results were compared between the two groups. ROC curve was used to determine the best cutoff points of NIC on arterial and venous phases. Taking pathological diagnosis as gold standard, the diagnostic values of NIC on arterial, venous and combined arteriovenous phases for NPC were analyzed.ResultsThe differences of NICs on arterial and venous phases between the two groups were statistically significant (both P<0.001). The areas under ROC of NICs on arterial and venous phases were 0.902 and 0.901 respectively, and the best cutoff points of NIC on arterial and venous phases obtained via analysis of the ROC were 0.124 and 0.229 respectively. Their sensitivities for the diagnosis of NPC were 88.33%, 90% and 83.33%, while the specificities were 83.75%, 85% and 90% respectively.ConclusionWith high values in the diagnosis of NPC, the NICs on arterial, venous and combined arteriovenous phases can be used as effective indicators for diagnosis of NPC by energy spectrum CT.

Key words:Nasopharyngeal neoplasm|Normalized iodine concentration|Receiver operating characteristic curve|Diagnostic value