全模型实时迭代重建对肝硬化患者腹部增强低剂量扫描的应用价值

Application of adaptive statistical iterative reconstruction V (ASIR-V) in contrast-enhanced abdominal scanning with low-dose for liver cirrhosis

目的探讨全模型实时迭代重建(ASIR-V)对肝硬化患者腹部增强CT低剂量扫描中的应用价值。方法前瞻性收集2017年6月至2018年5月郑州大学第一附属医院行上腹部CT增强扫描的肝硬化患者112例为试验组,依照肝功能Child-Pugh分级分为A、B和C级3组。对照组为非腹部病变而行腹部增强扫描且肝功能正常检查者30例。对照组各期均采用0前置ASIR-V,试验组平扫、动脉和门脉期分别采用30%、40%、50%前置ASIR-V,对照组和试验组均联合60%后置ASIR-V重建。图像质量的客观指标[腹主动脉、肝脏、胰腺、脾脏、门静脉对比噪声比(CNR)]和辐射剂量的比较采用单因素方差分析,主观评分比较采用Kruskal-Wallis H检验。结果同一期相试验组较对照组容积CT剂量指数、剂量长度乘积和有效剂量均减低(F=13.354~28.192,P<0.01),其中有效剂量下降分别1.12(23.9%)、1.54(33.5%)、2.14 mSv(46.7%)。门脉期肝脏、门静脉CNR值,Child C级组较Child A级组和对照组减低分别为0.34~0.42、0.43~0.49(q=2.851~4.658,P<0.05);平扫、动脉期各组间图像主观评分差异无统计学意义。门脉期Child C级组评分均值<3分,影响诊断,且与Child A和对照组差异有统计学意义(Z=26.734~29.218,P<0.05)。结论肝硬化患者依据肝功能分级联合前置ASIR-V,可在保证图像质量前提下降低辐射剂量。肝功能为Child-Pugh A或B级时,推荐使用前置50%ASIR-V;肝功能为Child-Pugh C级时,推荐使用前置40% ASIR-V。

Objective To investigate the application of adaptive statistical iterative reconstruction-V (ASIR-V) in contrast-enhanced abdominal CT scanning with low-dose for liver cirrhosis. Methods From June 2017 to May 2018, a total of 112 liver cirrhosis patients who underwent contrast-enhanced abdominal CT scanning were collected prospectively as the study group. According to Child-Pugh grading of liver function, the study group was divided into A, B and C groups. Thirty examiners with normal liver function who underwent contrast-enhanced abdominal CT scanning no abdominal diseases were collected as the control group. The control group applied 0 pre-ASIR-V. The study group applied 30%, 40% and 50% pre-ASIR-V in plain scanning, arterial and portal vein phase, respectively. The control and study group both combined with 60% post-ASIR-V. The difference of qualitative parameters (contrast to noise ratio of the liver, pancreas, spleen, abdominal aorta and portal vein), image noise and radiation dose were compared by One-way ANOVA. Subjective score of images were compared by Kruskal-Wallis H test. Results The volume computed tomography dose index (CTDIvol), dose length product (DLP) and the effective dose (ED) of study group were lower than the control group in the same phase (F=13.354-28.192, P<0.01). And the ED were decreased by 1.12 (23.9%), 1.54 (33.5%), 2.14 mSv (46.7%). The CNR values of liver and portal vein in Child C group was 0.34-0.42 and 0.43-0.49 lower than that of Child A and control group, respectively (q=2.851-4.658, P<0.05). Image noise had no difference in study and control group. There were no statistical differences between each group of subjective score in arterial and portal vein phase. The mean score of Child C in portal phase was lower than 3, which affected the diagnosis. And there were significant difference among the control, Child A and Child C group(Z=26.734-29.218, P<0.05). Conclusions According to the classification of liver function, liver cirrhosis combined with ASIR-V can ensure the image quality while reduce the radiation dose. When liver function is Child-Pugh A or B, preset 50%ASIR-V is recommended;40%ASIR-V is recommended for Child-Pugh C.