FBP、iDose~4和IMR重建算法对低剂量双下肢CTA图像质量的影响

发布时间：2018-03-23 20:37

本文选题：体层摄影术　切入点：X线计算机　出处：《中国医学影像技术》2017年02期

【摘要】：目的探讨滤波反投影(FBP)、混合迭代重建(iDose~4)和基于模型的迭代重建(IMR)技术对低剂量双下肢CTA图像质量的影响。方法对56例成年患者行双下肢CTA扫描,分别用FBP、iDose~4和IMR方法重建,测量下肢各段血管(腹主动脉分叉处、髂总动脉分叉处、股动脉近端、股动脉中段和乆动脉近端)的CT值、图像噪声及对比噪声比(CNR),并采用4分法对3组图像质量分别进行主观评分。结果 FBP、iDose~4和IMR重建图像的下肢各段血管平均CT值分别为(511.07±195.05)HU、(492.63±178.74)HU、(487.63±197.20)HU,三者间差异无统计学意义(F=1.175,P0.05)。图像噪声分别为(76.24±20.85)HU、(39.16±11.75)HU、(13.09±2.55)HU,三者间差异有统计学意义(F=1 460.000,P0.05)。CNR分别为6.35±3.14、12.97±5.10、33.83±15.85,三者间差异有统计学意义(F=646.122,P0.05)。图像质量主观评分IMR(3.75±0.46)、FBP(1.39±0.51)、iDose~4(2.61±0.81)差异有统计学意义(χ2=476.79,P0.05),膝关节以上、下段动脉可诊断率IMR(98.66%)明显高于FBP(1.34%)、iDose~4(56.70%),差异均有统计学意义(χ2=427.9,P0.05)。结论行低辐射剂量双下肢CTA扫描时,相比FBP和iDose~4,IMR可以显著降低图像噪声,提高图像质量,且能满足诊断要求。
[Abstract]:Objective to investigate the effects of filtered backprojection (FBP), mixed iterative reconstruction (IMR) and model-based iterative reconstruction (IMR) on the quality of low dose CTA images of lower extremities. Methods 56 adult patients were scanned with CTA of both lower extremities and reconstructed by FBPX iDose4 and IMR respectively. Ct values of lower extremity blood vessels (abdominal aorta bifurcation, common iliac artery bifurcation, proximal femoral artery, middle femoral artery and proximal femoral artery) were measured. The image noise and contrast noise ratio were compared. The image quality of the three groups was evaluated by the method of 4 points. Results the average CT values of the lower extremity vessels in the reconstructed images of IMR and FBP were 492.63 卤178.74HUA 487.63 卤1977.63 卤197.20HUU, respectively. There was no significant difference among the three groups. The image noise was 76.24 卤20.85hou (39.16 卤11.75hou) 13.09 卤2.55Hu, and the difference among them was statistically significant (6.35 卤3.146.97 卤5.10v 33.83 卤15.85, respectively). The subjective score of image quality was 1.39 卤0.561 卤0.51% (蠂 2 476.79), the difference was statistically significant (蠂 2 476.79), the knee joint was above 0. 05% (蠂 2 476.79), and there was a significant difference among them (蠂 2 476.79%, P 0. 05 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05, P 0. 05). The diagnostic rate of lower segmental artery was significantly higher than that of FBP 1.34 and iDose 46.70. The difference was statistically significant (蠂 2 / 427.9 / P 0.05N). Conclusion compared with FBP and iDose 4IMR, low radiation dose CTA can significantly reduce image noise, improve image quality and meet the diagnostic requirements.
【作者单位】：南京医科大学附属苏州医院放射科;
【分类号】：R816.2

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