迭代重建技术降低肝脏CT扫描辐射剂量的应用研究  

Application of iterative reconstruction technique to reduce the radiation dose of liver CT scan

作　　者：张信起[1] 王宁[1] ZHANG Xin-qi;WANG Ning(Department of Medical Imaging, the Second Affiliated Hospital of Hebei Medical University, Shijiazhuang 050000, China)

机构地区：[1]河北医科大学第二医院影像科,石家庄050000

出　　处：《中国医学前沿杂志（电子版）》2017年第8期141-145,共5页Chinese Journal of the Frontiers of Medical Science(Electronic Version)

摘　　要：目的评价迭代重建技术降低肝脏计算机断层成像(computer tomography,CT)扫描辐射剂量的可行性研究。方法选择2016年6月至2016年12月于本院就诊的临床疑似肝肿瘤、需行肝脏CT检查的120例患者为研究对象,根据随机数表法将入选患者分为A、B、C、D四组,每组各30例。A组和B组患者行常规剂量(120 k V,120 m As)CT扫描;C组和D组患者行低剂量(120 k V,80m As)CT扫描。A组和C组患者采用滤波反投影重建(filtered back projection,FBP)技术进行图像重建,B组和D组患者采用迭代重建技术进行图像重建。记录分析各组CT剂量指数(computed tomography dose index,CTDI)、CT剂量长度乘积(dose length produce,DLP)、有效辐射剂量(effective dose,ED)及图像对比噪声比(contrast to noise ratio,CNR),并评价各组CT扫描图像主观质量。对比分析各组数据,综合评价迭代重建技术降低辐射剂量的可行性。结果 B组患者CTDI、DLP、ED均显著低于A组(P<0.01),D组患者CTDI、DLP、ED均显著低于C组(P<0.01)。B组和D组患者噪声值均显著低于A组(P<0.01),CNR均显著高于A组(P<0.05);D组患者噪声值显著低于C组(P<0.01),CNR显著高于C组(P<0.01)。B组和D组噪声和伪影少的患者例数、诊断信心度高的患者例数、细微结构和病变显示清晰的患者例数均多于A组和C组(P<0.05)。结论迭代重建技术可在低于常规扫描剂量条件下提高肝脏CT扫描图像的质量,满足临床诊断需求,显著降低辐射剂量。Objective To evaluate the feasibility of using iterative reconstruction technique to reduce the radiation dose of liver computer tomography(CT)scan.Method120patients with clinically suspecting liver tumors and need examinated by CT in our hospital from June2016to December2016were randomly divided into group A,group B,group C and group D,group A and group B patients underwent conventional dose(120kV,120mAs)CT scan,group C and group D patients underwent low dose(120kV,80mAs)CT scan.The technology for image reconstruction of group A and group C were filtered back projection(FBP),and iterative reconstruction was used for group B and group D.CT dose index(CTDI),CT dose length product(DLP),effective radiation dose(ED)and the subjective quality of CT images in each group were recorded and analyzed.To evaluate the feasibility of IR technology to reduce the scanning dose by compared and analyzed the data of each group.Result The CTDI,DLP and ED of group B were significantly lower than those of group A(P<0.01),the CTDI,DLP and ED of group D were significantly lower than those of group C(P<0.01),CNR was significantly higher than that in group C(P<0.01).The noise values of group B and group D were significantly lower than those of group A(P<0.01),and CNR of group B and group D were significantly higher than that of group A(P<0.05).The noise value of group D was significantly lower than that of group C(P<0.01),and CNR was significantly higher than that of group C(P<0.01).The number of patients with less noise and artifact,higher confidence in diagnosis,more clear display of fine structures and lesions in group B and group D were significantly more than those of group A and group C(P<0.05).Conclusion Iterative reconstruction technology could improve the quality of hepatic CT scan image in lower dose than the conventional scanning to meet the requirements of clinical diagnostic,and can significantly reduce the radiation dose of CT scan diagnosis process in the clinical.

关 键 词：迭代重建 计算机断层成像 肝脏 图像噪声 低剂量 

分 类 号：R730.44[医药卫生—肿瘤] R735.7[医药卫生—临床医学]