螺旋CT低剂量扫描对肺结核病情监测的应用价值

Application value of spiral CT low-dose scanning in monitoring the condition of pulmonary tuberculosis

目的探讨64排128层螺旋CT低剂量扫描技术对于肺结核患者病情监测的应用价值。方法对我院120例经临床确诊的成人活动性继发性肺结核患者(痰涂片结核杆菌阳性)行64排CT检查,在其他扫描条件一致情况下分别采用常规120 mA及15～40 mA低剂量扫描,采用盲法阅片,记录每次扫描的CT容积剂量指数(CTDI_(vol))以及剂量长度乘积(DLP),根据有效剂量转换因子(K=0.014)估算每次CT检查所致有效剂量(ED),对比低剂量和常规剂量扫描和薄层重建的特殊影像表现,进行定量测量及差异分析。结果两种扫描方式对于实变、支气管扩张、空洞、磨玻璃密度影、钙化灶、树芽征、结节、胸膜肥厚、胸水等结核基本征象显示无明显差异,低剂量扫描受检者所受的X射线辐射剂量显著下降。结论飞利浦64排螺旋CT低剂量扫描技术和常规剂量相比,在保障检测效果的情况下,辐射剂量大幅度下降,可应用于肺结核的临床诊断及随访。

Objective To investigate the application value of 64-row 128-slice spiral CT low-dose scanning technique in monitoring the condition of pulmonary tuberculosis.Methods The 120 pulmonary tuberculosis patients diagnosed in our hospital were collected.Routine dose(120 mA)and the following Low-dose(15~40 mA)scanning were used with the same tube voltage of 120 Kv and other factors.Read a slice in a blind manner to record CT dose Index volume(CTDIvol)and dose-length product(DLP).Effective dose(ED)was estimated according to effective dose conversion factor.The special imaging manifestations of low-dose and conventional dose scanning and thin-layer reconstruction were compared for quantitative measurement and difference analysis.Results There was no significant difference between the two scanning methods in terms of the basic signs of tuberculosis,such as consolidation,bronchiectasis,cavitation,ground-class opacity,calcification,tree-in-bud sign,nodule,pleural hypertrophy and hydrothorax.The X-ray radiation dose received by the subjects in low-dose scanning decreased significantly.Conclusion Compared with the conventional dose,the low-dose scanning technique of PHILIPS 64-slice spiral CT can significantly reduce the radiation dose under the condition of guaranteeing the detection effect,which can be applied to the clinical diagnosis and follow-up of pulmonary tuberculosis.