模型迭代重组技术在低剂量CT增强中评价胃癌图像质量的可行性

发布时间：2018-05-09 00:34

本文选题：迭代模型重组技术 + 体层摄影术　；参考：《临床放射学杂志》2017年11期

【摘要】：目的比较滤波反投影(FBP)、高级迭代重组算法(iDose~4)、模型迭代重组技术(IMR)在胃癌CT增强扫描的图像质量和辐射剂量,评价IMR的临床应用价值。方法 40例患者按随机数表法分为低剂量组(A组)和常规剂量组(B组),每组20例,患者均行上腹部CT平扫和动态增强扫描,将门静脉期扫描数据作为研究对象。为保证图像质量,每组患者扫描时均固定噪声比(DRI),根据辐射剂量和重组算法不同将图像分为6组,包括A1组(120 kV,FBP),A2组(120 kV,iDose~4),A3组(120 kV,IMR),B1组(80 kV,FBP),B2组(80 kV,iDose~4),B3组(80kV,IMR)。分别比较A1、A2、A3组和B1、B2、B3组的图像质量客观评价指标[图像噪声、图像信噪比(SNR)、对比噪声比(CNR)]和主观评价指标(低对比分辨力、病灶边缘锐利度、图像失真和诊断信心度),并计算有效辐射剂量(ED)。结果低剂量组ED较常规剂量组平均降低73.7%。A组IMR重组的图像噪声显著低于FBP重组和iDose~4重组(P0.01),CNR及SNR显著高于FBP重组和iDose~4重组(P0.01);B组的客观评价结果同A组。A、B两组IMR重组的低对比分辨力(LCD)、病灶边缘锐利度(LES)、图像失真(ID)和诊断信心度(DC)优于FBP重组和iDose~4重组,其中,A1组和A3组,B1组和B2、B3组的差异有统计学意义(P0.05)。结论在显示胃癌病灶方面,IMR相比较iDose~4、FBP技术能大幅度降低图像噪声,提高图像质量。
[Abstract]:Objective to compare the image quality and radiation dose of filtered backprojection (FBP), advanced iterative recombination algorithm (IMR) and model iterative recombination (IMR) in CT enhanced scanning of gastric cancer, and to evaluate the clinical application value of IMR. Methods Forty patients were randomly divided into low dose group (group A) and routine dose group (group B, n = 20). All patients underwent plain CT scan and dynamic enhanced CT scanning. The data of portal vein phase scanning was used as the research object. In order to ensure the image quality, each group was divided into 6 groups according to radiation dose and recombination algorithm. The images were divided into 6 groups, including A 1 group (120 kV FBPU A 2) 120 kV iDose 3 group (120 kV) IMRN B 1 group 80 kV FBPU B 2 group 80 kV IMR. Objective evaluation indexes of image quality [image noise, image signal-to-noise ratio (SNR), contrast noise ratio (CNR)] and subjective evaluation index (low contrast resolution, edge sharpness) were compared between group A _ (1) and group A _ (1) A _ (2) and B _ (1) B _ (2) B _ (3), respectively. Image distortion and diagnostic confidence were measured and the effective radiation dose was calculated. Results the image noise of IMR recombination in low dose group was significantly lower than that in normal dose group 73.7.A was significantly lower than that in FBP recombination and iDose~4 recombinant P0.01CNR and SNR were significantly higher than that in FBP recombination and iDose~4 recombinant P0.01A group. Low contrast resolution, edge sharpness, image distortion and diagnostic confidence were superior to FBP and iDose~4 recombination. The difference between group A 1 and group A 3 was statistically significant (P 0.05). Conclusion IMR can significantly reduce image noise and improve image quality compared with iDose FBP.
【作者单位】：苏州大学附属第一医院放射科;
【分类号】：R730.44;R735.2

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