适应性统计迭代重建技术降低胸部CT扫描剂量的初步临床研究  

Radiation Dose Reduction in Chest CT Examination Using Adaptive Statistical Iterative Reconstruction Technique

作　　者：贾楠[1] 王新江[1] 惠萍[1] 李天文[1] 孙红[1] 李征芳[1] 

机构地区：[1]解放军总医院南楼放射科,北京100853

出　　处：《中国医学影像学杂志》2010年第6期551-553,共3页Chinese Journal of Medical Imaging

摘　　要：目的:分析适应性统计迭代(adaptive statistical iterative reconstruction,ASIR)重建技术降低胸部CT扫描中的X线剂量的作用。材料和方法:解放军总医院放射科胸部CT扫描的30名受检者,在2～14个月先后行64层MDCT和宝石探测器HDCT2次胸部CT检查,调取PACS系统两次胸部检查的剂量核查报表。64层MDCT图像重建为传统的滤过反投影法(filtered back projection,FBP),HDCT扫描中用适应性统计迭代重建(ASIR)技术,50%ASIR值重建图像。比较两种重建技术的肺动脉干平面降主动脉内CT值与标准差,测量比较两次检查胸部剂量CTDI与DLP。结果:30例受检者FBP重建法CTDI(CT Dose Index)为13.0±2.7mGy,DLP(Dose Lenghth Product)440.4±97.3mGy·cm;ASIR重建法平均CTDI6.2±1.5mGy,DLP207.2±53.1mGy·cm,两次检查的剂量差异有统计学意义(P<0.001)。肺动脉干平面降主动脉CT值分别为37.4±8.3Hu和38.1±9.8Hu,差异无统计学意义。结论:与传统CT重建图像的滤波反投影法相比,适应性统计迭代重建(ASIR)法胸部扫描中辐射剂量可降低50%以上,而图像噪声无明显提高。Purpose To assess radiation dose reduction in chest CT examination reconstructed with adaptive statistical iterative reconstruction（ASIR）technique.Method and Material Thirty subjects who had been undergone chest examination by both 64slices MDCT and Gemstone HDCT in our hospital in the past few months were enrolled in this study.They aged from 40yrs to 93yrs,averaged 72.2yrs,25males and 5 females were involved.The radiation lists of each examinitions were transferred to PACS automatically.The images were reconstructed traditionally by FBP in 64-slices MDCT,while the images were reconstructed by adaptive statistical iterative reconstruction（ASIR）in HDCT,ASIR value weighted to 50%.The CT value of descending aorta at the level of pulmonary artery trunk were measured as mean±SD（standard deviation）.The radiation lists of each examination were reviewed from PACS,the radiation dose was compared and analyzed.Result Of 30subjects,the averaged CTDI（CT Dose Index）is 13.02±2.65mGy in 64-slices MDCT,while it was only 6.21±1.53 mGy in HDCT,the DLP（Dose Lenghth Product）is 440.4±97.3mGy·cm in 64-slices MDCT and it is 207.2±53.1mGy·cm in HDCT,which showed radiation dose reduction over 50%.The CT value of descending aorta were 37.4±8.3Hu in 64-slices MDCT and 38.1±9.8Hu in HDCT,there is no statistical significance（t=-0.292,P=0.7717）.Conclusion ASIR helps reduce chest radiation dose in chest CT scanning compared to conventional FBP.

关 键 词：适应性统计迭代 体层摄影术 X线计算机 图像处理 计算机辅助 辐射剂量 胸部 

分 类 号：R816.4[医药卫生—放射医学]