迭代重建技术在256层CT腰椎低剂量扫描中的应用  

Application of Iterative Reconstruction Technique in 256-slice CT Low Dose Examination of Lumbar Vertebrae

作　　者：郑余泽[1] 唐颖[1] 汤伟军[1] 祝瑞江[1] 洪泳[1] 朱全东[1] 杨艳梅[1] 

机构地区：[1]复旦附属华山医院放射科

出　　处：《中国医学计算机成像杂志》2014年第2期195-199,共5页Chinese Computed Medical Imaging

摘　　要：目的:探讨迭代重建技术在256层CT腰椎扫描中降低辐射剂量的作用。方法:将60例临床要求行腰椎CT扫描的患者随机分为4组,分别采用常规参数(120kV、管电流自动调节:平均值为237mAs)、保持管电压/降低管电流(120kV、150mAs)、降低管电压/保持管电流(80kV、300mAs)、降低管电压/降低管电流的(80kV、150mAs)的扫描方法,原始数据分别经FBP(滤波反投影重建)和迭代技术进行图像重建,划定兴趣区测量图像噪声值,同时由3名经验丰富的放射科医生进行图像质量评分,运用CTDIv评估辐射剂量,将各数据进行统计学分析。结果:当扫描剂量降低时,图像质量下降、噪声增加;但相同扫描剂量两种重建技术比较,应用迭代重建技术能够提高图像质量、降低图像噪声(P<0.05)。结论:应用256层CT扫描中降低腰椎扫描剂量具有可操作性,迭代重建技术有助于在保证图像质量前提下,通过调整管电流和(或)管电压降低辐射剂量。Purpose： To evaluate the examination of lumbar vertebrae at 256-slice CT with iterative reconstruction technique to reduce radiation dose and preserve image quality. Methods： Sixty patients who suffered from lumbar diseases were randomly examined by CT using different scan parameters, which including 120kV with automatic tube current modulation （average value was 237mAs）, 120kV with tube current reduced to 150mAs, tube voltage reduced to 80kV with 300mAs, or both reduction of tube voltage to 80kV and tube current to 150mAs. The original images were reconstructed by FBP and iterative technique. The noise of images was measured in each group. Meanwhile three experienced radiologists evaluated the quality of images. CTDIv was used to measure the scan dose in each group. The data was analyzed in SPSS. Results： When scan parameters were changed and CTDIv was reduced, the image qualities were decreased and the noises were increased in both FBP and iterative reconstruction technique. Comparing both reconstruction techniques with the same scanning dose, the image quality of iterative reconstruction technique was higher and the noise was less （P〈0.05）. Conclusion： The iterative reconstruction technique in 256-slice CT may allow dose reduction without compromising image quality.

关 键 词：腰椎 CT 迭代重建 辐射剂量 

分 类 号：R816.8[医药卫生—放射医学]