3种不同迭代算法对腹部CT下腔静脉造影图像质量的影响  

Three different iterative reconstruction algorithms on abdominal CT image: a comparative study on image quality of the inferior vena cava

作　　者：谷春雨 张兆国 贾永军[1] 贺太平 张兰欣 GU Chunyu;ZHANG Zhaoguo;JIA Yongjun;HE Taiping;ZHANG Lanxin(Department of Radiology,the Affiliated Hospital of Shaanxi University of Chinese Medicine,Xianyang 7120OO,China;Shaanxi University of Chinese Medicine,Xianyang 712046,China)

机构地区：[1]陕西中医药大学附属医院医学影像科,陕西咸阳712000 [2]陕西中医药大学,陕西咸阳712046

出　　处：《实用放射学杂志》2018年第12期1949-1952,共4页Journal of Practical Radiology

摘　　要：目的比较自适应统计迭代重建(ASiR)和基于模型的迭代重建(MBIR)中优化降噪设置(MBIRwmo)与兼顾噪声与空间分辨率设置(MBIRSTND)3种重建算法扫描条件下对腹部CT下腔静脉造影图像质量的影响。方法随机收集行上腹部3期增强扫描受检者40例,选择注药后180s延迟期原始数据行ASiR(40%FBP和60%AS浓相结合的重建方式)、MBIRm。和MBIRSTND重建,层厚均为0.625mm。测量肝静脉分支层面的腹前壁皮下脂肪、左侧竖脊肌、下腔静脉、肝静脉(左支、右支)的CT值、噪声值,计算下腔静脉及肝静脉的对比噪声比(CNR),并以ASIR图像质量为标准,由2名放射科医师采用5分法对下腔静脉及肝静脉的主观噪声和光滑度、细小分支进行主观评价。结果常规腹部扫描条件下,MBIRNR40和MBIRSTND较ASIR主观噪声及血管光滑度、细小分支评分高,MBIRNR40图像的主观噪声及图像血管光滑度评分更高。结论MBIRNR40和MBIRSTND重建算法有助于提高下腔静脉及其分支血管造影CT图像的质量,优化降噪设置的MBIRNR40效果最优。Objective To evaluate the image quality improvement on abdominal CT imaging by using new model-based iterative reconstruction (MBIRn)in comparison with adaptive statistical iterative reconstruction (ASiR).Methods 40patients who underwent upper abdominal three-phase contrast-enhanced scan were included.After scanning,all the scans obtained at 180s later injection were reconstructed by three protocol,including ASiR (combined reconstruction of 40%FBP and 60%ASiR),the MBIRn of the noise reduction settings (MBIRNR40)and the spatinal resolution settings(MBIRsTND ).The thickness of the slice was 0.625mm.The values of CT and SD of the subcutaneous fat,left erector spinae,inferior vena cava and hepatic vein (left and right branches}were measured at the branch level of hepatic vein,and the contrast noise ratio (CNR)between inferior vena cava and hepatic vein were calculated.The subjective image quality was evaIuated by two radiologists according to the noise,smoothness and small branches of the inferior vena cava and hepatic vein using 5-scoring method.The quality images obtained from ASiR method were treated as reference standard.Results For MB^and MBIRNR40images,the subjective noise decreased and image quality increased comparing with ASiR images.Among which the MBIRNR40images had the best image with vascular smoothness score and the lowest subjective noise.Conclusion Compared with ASiR,MBIRsTnD and MBIRNR4O ,especially MBIRNR40improves the quality of CT images of the inferior vena cava and its branches.

关 键 词：基于模型的迭代重建 自适应统计迭代重建 下腔静脉 图像质量 

分 类 号：R814.42[医药卫生—影像医学与核医学] R816.5[医药卫生—放射医学]