迭代模型重建技术参数设置对肝脏低剂量增强CT扫描图像质量的影响

发布时间：2018-06-04 01:45

本文选题：肝脏 + 体层摄影术　；参考：《中国医学影像技术》2017年11期

【摘要】：目的探讨全模型迭代重建(IMR)技术不同参数设置对肝脏低剂量增强CT扫描图像质量的影响。方法收集需要接受肝脏增强CT检查的患者40例,分别行上腹部平扫和3期动态增强扫描,其中延迟期采用低剂量扫描,管电压80kV,管电流150mAs。对原始数据进行滤波反投射(FBP)重建和IMR技术重建,IMR采用不同参数,以获得不同水平(Level 1~3)的常规和软组织重建图像,分别记为R1、R2、R3亚组和S1、S2、S3亚组。对各组图像进行主观和客观评价并比较,主观评价包括低对比分辨率(LCD)、图像失真(ID)和诊断信心(DC)评分,客观评价包括肝脏噪声、信噪比(SNR)和对比噪声比(CNR)。结果不同参数组图像的LCD、ID和DC评分差异均有统计学意义(P均0.01)。不同参数组图像间噪声、SNR及CNR差异均有统计学意义(P均0.01);除S1与R2亚组、S2与R3亚组3项指标(P均0.05)外,余两两比较差异均有统计学意义(P均0.01)。结论全迭代重建IMR技术可提高肝脏低剂量增强CT扫描的图像质量,推荐参数为软组织重建、Level 1或常规重建、Level 2。
[Abstract]:Objective to investigate the effect of different parameters on the quality of liver low dose enhanced CT scanning with full model iterative reconstruction (IMR) technique. Methods A total of 40 patients who needed to be examined with enhanced liver CT were examined by plain upper abdominal scan and 3 phase dynamic enhanced scan respectively. The delayed phase was performed with low dose scan, the tube voltage was 80 kV, and the tube current was 150 mAs. The conventional and soft tissue reconstruction images of the original data were obtained by using different parameters to obtain the normal and soft tissue reconstruction images of different levels of level 1 ~ (3), respectively, which were recorded as the R1 ~ (2 +) R _ (2) subgroup and S _ (1) S _ (2) S _ (3) subgroup respectively. The subjective and objective evaluation of each group included low contrast resolution (LCD), image distortion (IDD) and diagnostic confidence (DC) score. Objective evaluation included liver noise, SNR (SNR) and contrast noise ratio (CNRR). Results there were significant differences in LCDID and DC scores between different parameter groups (P < 0.01). There were significant differences in CNR and SNR between different parameter groups (P < 0.01), except for S _ 1 and R _ 2 subgroup S _ 2 and R _ 3 subgroup (P 0.05), there were significant differences between the other two groups (P < 0.01). Conclusion Total iterative reconstruction IMR technique can improve the image quality of liver low-dose enhanced CT scan. The recommended parameters are soft tissue reconstruction level 1 or conventional reconstruction level 2.
【作者单位】：第二军医大学长征医院影像科;
【分类号】：R575;R816.5

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