优化扫描剂量在儿童胸部病变MSCT检查中的应用价值

Application value of optimizing low-dose for infant chest MSCT scanning

目的探讨多层螺旋CT(multi-slice spiral computed tomography,MSCT)低管电流扫描技术在儿童胸部病变中的应用价值。方法300例可疑胸部病变患儿随机分为50 mA低剂量扫描组、自动管电流调节技术(automatic tube current modulation,ATCM)组及100 mA常规剂量扫描组,每组各100例。所选患儿进行MSCT检查,记录扫描中患儿所接收的辐射剂量,并对图像质量进行评估。结果50 mA组、ATCM组及100 mA组三组患儿的客观噪声分别为11.99±4.92、10.78±1.14、9.09±0.85。3组的有效剂量ED分别为(0.94±0.11)mSv、(1.34±0.37)mSv、(1.87±0.17)mSv。3组不同剂量扫描组的肺窗及纵隔窗图像质量均满足临床诊断要求。3组1级、2级和3级图像数量比较,差异均无统计学意义(P>0.05)。结论采用50 mA管电流进行儿童胸部MSCT扫描,肺窗及纵隔窗的图像质量均可满足诊断。合适的低剂量MSCT扫描不仅可降低辐射剂量,同时可降低球管的消耗、延长机器的使用寿命,符合放射防护最优化的原则。

Objective To evaluate the application of the optimizing low-dose for infant chest multi-slice spiral computed tomography(MSCT)scanning.Firstly,300 children diagnosed as suspected cases of chest diseases were chosen as the subjects of study and then were randomly divided into three groups,namely,50 mA low-dose scan group(n=100),automatic tube current modulation(ATCM)scan group(n=100),and the regular 100 mA dose scan group(n=100).Secondly,the three groups were subjected to MSCT scanning.The radiation dose the subjects were exposed to was recorded and the imaging quality was evaluated.Results The objective noise and mean effective dose of the 50 mA low-dose scan group,the ATCM group and the regular 100 mA dose scan group was 11.99±4.92,10.78±1.14,and 9.09±0.85,respectively.The mean effective dose of the three groups were(0.94±0.11)mSv,(1.34±0.37)mSv,and(1.87±0.17)mSv,respectively.The image quality of the lung window and mediastinal window in three groups with different scanning doses met the clinical diagnosis requirements.No significant difference was found among the three groups in the number of grade 1,2 and grade 3 images(P>0.05).Conclusions The image quality of lung window and mediastinal window of chest obtained by 50 mA low-dose scan in the pediatrics can satisfy the requirements of diagnosis.Proportionate low-dose MSCT scan can not only reduce the radiation dose,but also reduce the tube consumption and hence extend the life of the machine,which the principle of optimal radiation protection asks for.