甲状腺常见单发结节低剂量CT灌注分析

Analysis of Low Dose CT Perfusion in Common Solitary Thyroid Nodules

目的:探讨甲状腺单发结节的低剂量CT灌注特征,旨在初步研究低剂量CT灌注在甲状腺常见单发结节鉴别诊断中的价值。方法:比较分析20例良性单发结节和10例恶性单发结节的CT灌注表现,通过两独立样本秩和检验及进一步判别分析总结其对甲状腺单发结节性质判断的价值。结果:经两独立样本秩和检验,良恶性甲状腺结节血流量(BF)中位数分别为391.81 m L·100 g^(-1)·min^(-1)、602.10 m L·100 g^(-1)·min^(-1);平均通过时间(MTT)中位数分别为4.76 s、2.19 s;毛细血管通透性(PS)中位数分别为22.24 m L·100 g^(-1)·min^(-1)、26.11 m L·100 g-1·min-1;差异有统计学意义。Z值与P值分别为-2.222、0.024;-4.072、0.000;-2.246、0.021;经过Fisher判别分析,以MTT及PS建立判别公式(F值与P值分别为12.808、0.000),回顾性误判本组甲状腺单发结节诊断准确率为87.5%。结论:低剂量CT灌注可反映甲状腺常见单发结节微循环特征,为鉴别诊断提供帮助。

Objective： To investigate the low dose perfusion CT characteristics of solitary thyroid nodules in order to study the value of low dose perfusion CT in the differential diagnosis of common solitary thyroid nodules. Methods： Perfusion CT findings of 20 cases of benign nodules and l0 malignant nodules were compared and analyzed. Two independent sam- ple rank-sum test was used to further summarize its value in deciding the nature of solitary thyroid nodules. Results： Me- dian of blood flow （BF） of benign and malignant thyroid nodules was 391.81 mL · 100 g-1 . min-1 and 602.10 mL · 100 g^- 1 · min^-1 respectively; median of mean transit time （MTT） was 4.76 S and 2.19 S respectively ; median of per- meability surface （PS） was 22.24 mL ·100 g^-1 . min^-1 and26.11 mL · 100 g-1 · min-1 respectively. The difference was statistically significant. Z value of BF, MTT and PS were - 2. 222, - 4. 072, and - 2. 246 respectively. P value of BF, MTY and PS were 0. 024,0.000 and O. 021 respectively. After Fisher diseriminant analysis, MTT and PS were used to establish the discriminant equation （ F value were 12. 808, P value were 0.000） ; the diagnostic accuracy rate in our data was 87.5 %. Conclusion： Low dose perfusion CT can reflect the microcirculation characteristics of common solitary thy- roid nodules, which contributes to differential diagnosis.