双能量CT有效原子序数联合碘浓度在甲状腺乳头状癌鉴别诊断中的初步研究

The Preliminary Research of Effective Atomic Number Combined with Iodine Concentration from Dual-Energy CT in the Differential Diagnosis of Thyroid Papillary Carcinoma

摘要: 目的：探讨双能量增强CT动脉期有效原子序数(Zeff)与标准化碘浓度(NIC)在甲状腺乳头状癌(PTC)与常见良性结节的鉴别诊断价值。方法：回顾性分析经手术病理证实的60例甲状腺结节患者(PTC 16例，结节性甲状腺肿34例，腺瘤10例)的动脉期双能量CT资料，测量并比较三组间Zeff与NIC值，采用Kruskal-Wallis检验及两两比较分析组间差异，并基于有统计学意义的组别，绘制ROC曲线评估参数的诊断效能。结果：动脉期NIC与Zeff在三组间总体差异显著(P < 0.05)。两两比较显示，PTC组动脉期Zeff与NIC值均显著高于结节性甲状腺肿组(均P < 0.01)，而PTC组与腺瘤组、结节性甲状腺肿组与腺瘤组之间，上述参数的差异均无统计学意义(均P > 0.017)。在PTC与结节性甲状腺肿的鉴别中，动脉期NIC的诊断效能最高(AUC = 0.770)，其最佳截断值为0.17，对应的灵敏度与特异度分别为81.3%与67.6%；动脉期Zeff虽AUC稍低(0.737)，但灵敏度极佳(93.8%)。结论：动脉期NIC是鉴别PTC与结节性甲状腺肿的稳定指标，而Zeff具极高的灵敏度在排除诊断中价值突出。然而，二者在鉴别PTC与腺瘤时效能有限，临床应用时需结合其他检查方法综合判断。

Abstract: Objective: To evaluate the diagnostic value of dual-energy CT (DECT) parameters, the effective atomic number (Zeff) and normalized iodine concentration (NIC) in the arterial phase, for differentiating thyroid papillary carcinoma (PTC) from common benign nodules. Methods: We retrospectively analyzed arterial-phase DECT data from 60 patients with pathologically confirmed thyroid nodules (16 PTC, 34 nodular goiters, 10 adenomas). Zeff and NIC values were measured and compared across the three groups using Kruskal-Wallis tests with post-hoc pairwise comparisons. For groups showing significant differences, we constructed ROC curves to assess diagnostic performance. Results: Significant overall differences in arterial-phase NIC and Zeff were observed among the three groups (P < 0.05). Pairwise comparisons specifically revealed that both parameters were significantly higher in the PTC group than in the nodular goiter group (all P < 0.01). No significant differences were found between PTC and adenoma groups, or between nodular goiter and adenoma groups (all P > 0.017). For discriminating PTC from nodular goiter, arterial-phase NIC demonstrated the highest diagnostic efficacy (AUC = 0.770) with an optimal cutoff of 0.17, yielding 81.3% sensitivity and 67.6% specificity. Although arterial-phase Zeff had a slightly lower AUC (0.737), it showed excellent sensitivity (93.8%). Conclusion: Arterial-phase NIC serves as a reliable indicator for distinguishing PTC from nodular goiter, while Zeff provides outstanding value for ruling out malignancy due to its high sensitivity. However, both parameters show limited utility in differentiating PTC from adenoma, necessitating integration with other diagnostic modalities in clinical practice.