超低辐射剂量扫描在CT引导下经皮肺穿刺活检中的应用

Application of ultra-low radiation dose scanning in CT-guided percutaneous lung biopsy

目的:探讨超低辐射剂量多层螺旋CT(MSCT)扫描方案进行CT引导下经皮肺穿刺活检的可行性。方法:根据扫描条件的不同,将90例进行CT引导下经皮肺穿刺活检的患者分为A、B、C三组。A组:管电压80 kV,管电流55 mA;B组:管电压110 kV,管电流55 mA;C组:管电压120 kV,管电流为自动毫安秒。图像质量的客观评价指标为信号噪声比(SNR)和对比噪声比(CNR)。由两名医生共同对CT引导下穿刺针扫描的图像进行主观评分。记录、计算患者的容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)及有效剂量(ED),并以扫描长度5 cm计算患者的标准化ED(ED标准化)。三组受检者的年龄、DLP、ED、SNR和CNR的差异采用方差分析,存在统计学差异再采用LSD检验进行组间两两比较。图像质量的主观评分差异采用χ2检验。结果:90例患者均成功完成CT引导下经皮肺穿刺活检术。三组受检者的性别、年龄、体质量指数(BMI)差异均无统计学意义(P均>0.05)。三组图像质量的主观评价均满足穿刺需求(≥2分);三组的图像质量主观评分(穿刺针路径的显示)差异无统计学意义(χ2=2.56,P=0.235)。A组的图像SNR及CNR均低于B、C组(P均<0.05)。相对于B组,A组的DLP、ED和ED标准化分别降低约44.16%、44.13%、39.29%;相对于C组分别降低约78.52%、76.31%、73.02%。结论:超低辐射剂量CT引导下经皮肺穿刺活检可显著降低辐射剂量而不影响穿刺针路径和穿刺部位的观察。

Objective:To investigate the feasibility of CT-guided percutaneous lung biopsy with ultra-low radiation dose multi-slice spiral CT(MSCT)scanning scheme.Methods:We prospectively enrolled 90 patients with pulmonary lesions,which were randomly divided into A,B,and C groups according to the scanning.The scanning parameters were as follow:Group A,tube voltage 80 kV,tube current 55 mA;Group B,tube voltage 100 kV,tube current 55 mA;Group C,tube voltage 120 kV,tube current defined as automatic milliamp seconds.Signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were considered as objective indicators.Subjective scoring of the CT-guided needle scan images was performed by two experienced radiologists.The patient’s volume dose index(CTDIvol),dose length product(DLP),effective dose(ED),and standardized effective radiation dose were recorded.The standard ED was calculated within 5 cm scanning range.The differences of age,DLP,ED,signal,noise,SNR and CNR among three groups were compared by ANOVA analysis and intergroup comparison was performed with LSD test.The differences of gender,image quality and subjective scores in three groups were compared by Chi square test.Results:All the 90 patients successfully completed CT-guided percutaneous lung biopsy.There were no statistically significant differences in terms of gender,age,height,body mass index among the three groups(P>0.05).The subjective evaluation of the image quality of the three groups all met the need for puncture(≥2 points)and showed no statistically significant(χ~2=2.56,P=0.235).The SNR and CNR of group A were lower than those of group B and group C(all P<0.05).Compared with group B,DLP,ED,and ED standardization in group A were reduced by approximately 44.16%,44.13%,and 39.29%,respectively;compared with group C,they were reduced by approximately 78.52%,76.31%,and 73.02%,respectively.Conclusion:Percutaneous lung biopsy guided by ultra-low radiation dose CT can significantly reduce the radiation dose without affecting the observation of the needle path and puncture site.