噪声指数在CT定位肺部穿刺活检中的应用

The application of noise index in CT localization lung puncture biopsy

目的:探讨螺旋CT噪声指数技术(noise index,NI)在肺部CT引导下穿刺定位的应用价值。方法:选取30例进行CT引导下穿刺活检的患者,首次扫描采用胸部剂量(60 kV、100 mAs,NI20)扫描滤波反投影重建,后续监测穿刺针插入肿瘤过程扫描依次采用较高噪声(NI40)和高噪声指数(NI60)。记录每次扫描的容积CT剂量指数,剂量长度乘积,并计算有效剂量。结果:三种噪声指数剂量比较辐射剂量分别降低了47%与77%。3组的图像质量均能满足穿刺活检检查监测穿刺针的诊断要求。结论:将噪声指数技术应用到低剂量CT引导下穿刺活检定位中,可以大幅降低辐射剂量,值得临床推广。

Objective:To explore the value of spiral CT noise index technique in lung CT guided puncture localization.Methods:Thirty patients were selected for CT-guided puncture biopsy.The first scan was performed with chest dose(60 kV,100 mAs,NI20)scan filtering and back projection reconstruction,followed by follow-up monitoring of puncture needle insertion process and followed by higher noise(NI40)and highest noise index(NI60).The volumetric CT dose index,dose length product and effective dose were recorded for each scan.Results:The radiation doses of the three noise index doses were reduced by 47%and 77%respectively.The image quality of the three groups can meet the diagnostic requirements of puncture biopsy monitoring needle.Conclusion:The application of noise index technique to low dose CT guided puncture biopsy localization can significantly reduce the radiation dose,which is worthy of clinical promotion.