多层螺旋CT诊断甲状腺癌中的辐射和对比剂剂量选择

本文对多层螺旋CT（MSCT）诊断甲状腺癌中的辐射和对比剂剂量选择进行了分析。选取2016年12月～2018年12月本院行MSCT检查的甲状腺癌、甲状腺良性结节患者各200例，依据随机数字表分为A组、B组、C组、D组，每组50例，A组参数为对比剂1.2 mL/kg、120 kV、180 mA，B组为对比剂1.0 mL/kg、120 kV、180 mA，C组为对比剂1.2 mL/kg、100 kV、100 mA，D组为对比剂1.0 mL/kg、100 kV、100 mA。结果显示，A组和B组CT容积剂量指数（CTDIvol）、剂量长度乘积（DLP）、有效辐射剂量（ED）明显低于C组和D组，A组和B组甲状腺CT值、背景信号、背景噪声明显高于C组和D组，差异有统计学意义（P<0.05），A组、B组、C组、D组信噪比（SNR）、对比信噪比（CNR）、图像质量评分比较，差异无统计学意义（P>0.05）；A组、B组、C组、D组诊断甲状腺癌的敏感度、特异度、准确度比较，差异无统计学意义（P>0.05）。本文证实，对于MSCT诊断甲状腺癌中的辐射和对比剂剂量，选择1.0 mL/kg、100 kV、100 mA可在不严重影响图像质量及检查结果下有效减少患者的CT辐射，值得临床推广。

The Radiation and Contrast Agent Dosage Selection of Multi-slice Spiral CT in the Diagnosis of Thyroid Cancer

To discuss the radiation and contrast agent dosage selection of multi-slice spiral CT (MSCT) in the diagnosis of thyroid cancer, 200 patients with thyroid cancer or benign thyroid nodules underwent MSCT examination were selected as the subjects of this study from December 2016 to December 2018 in our hospital. They were divided into group A, group B, group C and group D, 50 cases in each group. The parameters of group A were 1.2 mL/kg of contrast agent, 120 kV and 180 mA, group B was 1.0 mL/kg of contrast agent, 120 kV and 180 mA, group C was 1.2 mL/kg of contrast agent, 100 kV and 100 mA, group D was 1.0 mL/kg of contrast agent, 100 kV, 100 mA. The results showed that, the CT volume dose index (CTDIvol), dose length product (DLP), effective radiation dose (ED) in group A and group B were significantly lower than those in group C and group D, the thyroid CT value, background signal, background noise in group A and group B were significantly higher than those in group C and group D, the difference was statistically significant (P<0.05), and there was no significant difference in SNR, CNR and image quality score between group A, group B, group C and group D (P>0.05). There was no significant difference in sensitivity, specificity and accuracy of thyroid cancer diagnosis between group A, group B, group C and group D (P>0.05). This study confirms that, in the radiation and contrast agent dosage selection of MSCT in the diagnosis of thyroid cancer, the 1.0 mL/kg, 100 kV and 100 mA can effectively reduce the CT radiation of patients without seriously affecting the image quality and examination results. It is worth for further clinical promotion.