低剂量与常规剂量螺旋CT鉴别肺结节的对比研究

Comparative study of the standard dose and low-dose spiral CT in detection of pulmonary nodules

目的 研究低剂量与常规剂量螺旋CT在检测肺结节的数目、肺结节内部与周边特征上是否有显著差异。方法 对常规剂量（200mA）与层厚（10mm）扫描中发现肺结节患者再进行常规剂量5mm层厚及低剂量（25mA）5mm、10mm层厚共4次螺旋CT扫描，再按〈5mm、5～10mm、〉10mm不同大小分组记录结节数目，并记录结节形状、内部特征以及边缘特点。最后采用χ^2检验分析低剂量扫描以及常规剂量扫描各组间结节的数目及其内部、周边结构的差异是否有统计学意义。结果 低剂量与常规剂量螺旋CT5mm、10mm层厚扫描在检测肺结节的数目、肺结节内部与周边特征无统计学意义（P〉0．05）。结论 25mA低剂量螺旋CF扫描可对肺结节的质与量可做出良好判定，值得在人群普查、肺结节复查中推广应用。

Objective To compare the performance of the standard dose and low-dose scanning protocol in detecting the number and central and peripheral structure of pulmonary nodules at spiral CT. Methods All patients were undergone CT exanination at the standard dove （200mA, collimation 5mm and 10 mm） and low-dove （25mA, collimation 5mm and 10nm0. According to the size, the nodules were categorized as 〈 5 mm, 5-10 mm and 〉 10mm nodules. The number and central and peripheral structure of the nodule were recorded and compared between the standard dose and low-dose scanning protocol groups. The statistical method X2 test was used to analyze the performance between the standard dose and low-dose protocols. Results There was no significant difference in the number, central and peripheral structure of the nodules detected by the standard dose from the low- dose spiral CT scanning. Conclusion The 25mA low-dose spiral CT scanning could provide adequate images to detect or exclude pulmonary nodules, thus, it might be used reliably in general examination of pulmonary nodules.