基于模型迭代重建联合纹理增强设置在低剂量上腹部CT检查中的应用  

Application of model-based iterative reconstruction combined with texture enhancement setting in low-dose upper abdominal CT examination

作　　者：郭长义[1,2] 贾永军 贺太平 杨创勃 刘辉[1] 张喜荣[2,3] GUO Changyi;JIA Yongjun;HE Taiping;YANG Chuangbo;LIU Hui;ZHANG Xirong(Yimai Sunshine Image Center,Second Affiliated Hospital of Shaanxi University of Chinese Medicine,Xianyang,Shaanxi 712000,China;Shaanxi University of Chinese Medicine,Xianyang,Shaanxi 712000,China;Affiliated Hospital,Shaanxi University of Chinese Medicine,Xianyang,Shaanxi 712000,China)

机构地区：[1]陕西中医药大学第二附属医院一脉阳光影像中心,陕西咸阳712000 [2]陕西中医药大学,陕西咸阳712000 [3]陕西中医药大学附属医院,陕西咸阳712000

出　　处：《现代医药卫生》2020年第15期2350-2353,2356,共5页Journal of Modern Medicine & Health

摘　　要：目的探讨基于模型迭代重建(MBIR)联合纹理增强设置(MBIR TX)在低剂量上腹部CT检查中的应用。方法采用能谱CT扫描静态水模型,比较0.625 mm层厚滤波反投影法(FBP)、自适应统计迭代重建(ASIR)、MBIR、MBIR联合MBIR TX重建图像的空间和密度分辨率。常规剂量采用FBP,低剂量采用标准FBP、ASIR、MBIR和MBIR TX重建厚度0.625 mm的图像。比较不同重建算法同一部位皮下脂肪、背部肌肉、肝脏、脾脏(感兴趣区)噪声,以及肝脏、脾脏的对比噪声比(CNR)。由2名影像科医生采用盲法对重建图像进行评分(-3^+3分),对不同重建算法所获的上腹部CT图像质量进行主观评价。结果在空间分辨率和密度分辨率方面,MBIR联合MBIR TX明显优于其他重建算法,且与MBIR比较,MBIR TX图像中的纹状伪影相对较少。在图像噪声方面,低剂量MBIR联合MBIR TX均低于常规剂量FBP和低剂量ASIR和FBP,而CNR则相对较高,差异均有统计学意义(P<0.05)。在主观评价方面,与常规剂量比较,低剂量MBIR联合MBIR TX具有明显优势,且能更为清晰地显示上腹部的细节结构及病灶边缘特征。结论与传统剂量FBP比较,低剂量(即减少辐射剂量约75%)MBIR联合MBIR TX上腹部重建成像可获得更高质量的图像;MBIR TX可解决MBIR中存在条纹伪影的问题,在显示细节结构和病变边缘特征方面具有显著优势。Objective To investigate the clinical application of model-based iterative reconstruction with texture enhancement setting(MBIR TX)in low-dose upper abdominal CT examination.Methods The energy spectrum CT scanning static water model was adopted.The space and density resolution of 0.625 mm filter backprojection(FBP),adaptive statistical iterative reconstruction(ASIR),MBIR,MBIR combined with MBIR TX reconstruction image were compared.The routine dose adopted FBP,the low dose adopted the standard FBP,ASIR,MBIR and MBIR TX reconstruction thickness 0.625mm image.The noises of subcutaneous fat of the same part,dorsal muscle,liver and spleen(interesting region)and the contrast noise ratio(CNR)of liver and spleen were compared.The two radiologists adopted the blind method to score the reconstruction image(-3-+3 points).The upper abdominal CT image obtained by different reconstruction algorithms conducted the subjective evaluation.Results In the aspects of spatial resolution and density resolution,MBIR combined with MBIR TX was significantly superior to the other algorithms,moreover compared with MBIR,the texture artifacts in MBIR TX image was relatively less.In the aspect of image noise,low dose MBIR combined with MBIR TX was lower than the routine dose FBP and low dose ASIR and FBR,but the CNR was relatively high,and the differences were statistically significant(P<0.05).In the aspect of subjective evaluation,compared with the routine dose,low dose MBIR combined with MBIR TX had significant superiority,moreover which could more clearly display the details of the construction in upper abdomen and characteristics of lesion margin.Conclusion Compared with the traditional dose FBP,the low dose(decreasing the radiation dose by 75%)MBIR combined with MBIR TX upper abdominal reconstruction image can obtain much higher quality of image;MBIR TX can resolve the texture artifact problem existing in MBIR and has significant superiority in the aspect of displaying the details of construction and characteristics of lesion edge.

关 键 词：辐射剂量 体层摄影术 X线计算机 腹部 基于模型的迭代重建 自适应统计迭代重建 

分 类 号：R816.5[医药卫生—放射医学] R445.3[医药卫生—临床医学]