新一代基于模型的迭代重建在低剂量上腹部CT中的应用效果及对CT图像质量的影响

Application effect of new version of model-based iterative reconstruction in low-dose upper abdominal CT and its influence on CT image quality

目的探讨新一代基于模型的迭代重建(MBIRn)在低剂量上腹部电子计算机断层扫描(CT)中的应用效果及对CT图像质量的影响。方法选取2019年5月至2021年5月在本院接受低剂量上腹部CT检查的56例患者作为研究对象。低剂量上腹部CT扫描并完成图像采集后,分别行滤波反投影算法(FBP)、MBIR_(NR40)处理。比较两种方法的应用效果。结果MBIR_(NR40)的剂量长度乘积(DLP)、有效剂量(ED)低于FBP,差异具有统计学意义(P<0.05)。MBIR_(NR40)的背部肌肉、皮下脂肪、肝脏、脾脏实质噪声低于FBP,差异具有统计学意义(P<0.05);MBIR_(NR40)的肝脏、脾脏实质信号噪声比(SNR)高于FBP,差异具有统计学意义(P<0.05)。两名医生采用MBIR_(NR40)的噪声、伪影、诊断信心、小结构显示、病变显示评分均低于FBP,差异具有统计学意义(P<0.05)。结论低剂量上腹部CT中采用MBIR_(NR40)可有效降低辐射剂量、噪声,有助于提升SNR与图像质量。

Objective To explore the application effect of new version of model-based iterative reconstruction(MBIRn)in low-dose upper abdominal computed tomography(CT)and its influence on CT image quality.Method A total of 56patients who underwent low-dose upper abdominal CT examination in our hospital from May 2019 to May 2021 were selected as the research objects.After low-dose upper abdominal CT scan and image acquisition,filtered back projection(FBP)and MBIR_(NR40)processing were performed respectively.The application effects of the two methods were compared.Results The does length product(DLP)and effective dose(ED)in the MBIR_(NR40)were lower than those in the FBP,and the differences were statistically significant(P<0.05).The noise of back muscle,subcutaneous fat,liver and spleen parenchyma in the MBIR_(NR40)were lower than those in the FBP,and the differences were statistically significant(P<0.05).The signal-tonoise ratio(SNR)of liver and spleen parenchyma in MBIR_(NR40)were higher than those in FBP,and the differences were statistically significant(P<0.05).The scores of noise,artifacts,diagnostic confidence,small structure display and lesion display of MBIR_(NR40)were lower than those of FBP,and the differences were statistically significant(P<0.05).Conclusion MBIR_(NR40)used in low-dose upper abdominal CT can effectively reduce radiation dose and noise,and improve SNR and image quality.