能谱CT诊断甲状腺良恶性结节的价值

Investigation on the value of spectral CT imaging in diagnosis of benign and malignant thyroid nodules

目的 探讨CT能谱成像对甲状腺良恶性结节的检出及鉴别诊断价值.方法 回顾性分析经病理证实的88例甲状腺结节患者能谱CT图像,所有患者均行颈部能谱CT平扫,其中33例同时行双期增强扫描.根据病理结果,将结节分为良、恶性两组,采用Wilcoxon秩和检验比较两组平扫及增强扫描碘浓度、能谱曲线斜率和有效原子序数.绘制ROC曲线,得出最佳诊断阈值及诊断的敏感度和特异度.结果 88例患者共检出甲状腺结节106个,其中良性76个、恶性30个.两组平扫期碘浓度、曲线斜率、有效原子序数的中位数,良性组分别2.35×100 μg/ml、0.29和7.71,恶性组分别为-0.51×100 μg/ml、-0.06和7.52,差异均有统计学意义（Z值分别为-3.072、-3.107和-3.055,P值均＜0.05）；动脉期碘浓度、曲线斜率、有效原子序数的中位数,良性组分别27.22×100 μg/ml、3.23和9.10,恶性组分别为18.81×100 μg/ml、2.24和8.69,差异也均有统计学意义（Z值分别为-2.582、-2.582和-2.564,P值均＜0.05）.静脉期两组各项参数差异均无统计学意义（P值均＞0.05）.平扫期诊断甲状腺恶性结节最佳碘浓度值为-0.35×100 μg/ml,敏感度为56.7％,特异度为73.7％.动脉期最佳碘浓度为22.91×100 μg/ml,敏感度为76.2％,特异度为75.0％.结合平扫、动脉期碘浓度诊断恶性结节,敏感度为81.2％,特异度73.3％,准确度81.6％,高于单独平扫或动脉期.结论 能谱CT成像能够定量评估甲状腺结节碘含量,对鉴别结节良恶性有一定价值.

Objective To explore the value of gemstone spectral imaging （GSI） in the detection and differential diagnosis of benign and malignant thyroid nodules.Methods The spectral CT images in 88 patients with thyroid nodules were analyzed retrospectively.All the patients underwent spectral CT scanning,including 33 patients undergoing biphase enhanced CT imaging.Nodules were divided into benign and malignant ones according to histopathologic results.The iodine concentration,slope of spectral curve,effective atomic number in non-enhanced and enhanced scanning were compared between benign and malignant group by the Wilcoxon rank sum test,respectively.The optimal iodine concentration threshold to predict malignancy was obtained by receiver operating characteristic curve （ROC）,sensitivity and specificity were achieved.Results A total of 106 nodules were detected,including 76 benign and 30 malignant nodules.In non-contrast CT imaging,the average iodine concentration,slope of spectral curve,effective atomic number of were 2.35×100 μg/ml,0.29 and 7.71 for benign group：-0.51 ×100 μg/ml,-0.06 and 7.52 for malignant group （Z value were-3.072,-3.107 and-3.055,respectively ; P 〈 0.05）.In the arterial phase,the average iodine concentration,slope of spectral curve,effective atomic number of the two group were 27.22 ×100 μg/ml,3.23 and 9.10 for benign group; 18.81 ×100 μg/ml,2.24 and 8.69 for malignant group （Z value were-2.582,-2.582 and-2.564,respectively; P 〈 0.05）.In venous phase,no significant difference was found for each parameter between the two groups （P 〉 0.05）.The optimal iodine concentration to predict malignancy was-0.35 × 100 μg/ml in non-enhanced phase with 56.7% sensitivity and 73.7% specificity.The optimal iodine concentration was 22.91×100 μg/ml in arterial phase,with 76.2% sensitivity and 75.0% specificity.Using iodine concentration to predict malignancy in both noncontrast phase and arterial phase,the sensitivity and specificity were 81.2% and 73.3%,while the accuracy was 81.6%.Conclusion Gemstone spectral CT imaging can quantitatively evaluate the iodine content of thyroid nodules,having a potential value in differential diagnosis of thyroid nodules.