基于能谱CT单能量成像及自适应统计迭代重建技术的门静脉图像质量分析

发布时间：2019-03-12 12:02

【摘要】：目的:探讨和评价采用宝石能谱CT单能量成像及自适应统计迭代重建(ASiR)技术门静脉图像的质量,并将其与传统多排螺旋CT的门静脉图像进行对比分析。方法:搜集临床有恶性肿瘤病史、治疗后随诊行上腹部增强扫描检查的患者90例,按照数字表法随机分为A组(最佳CNR单能量组)、B组(60keV+40%ASiR组)及C组(常规螺旋CT组),每组30例。A组门静脉期采用能谱扫描模式扫描,双电压快速切换;从扫描数据中重组出40~140keV能量段的101组单能量图像,得出门静脉主干CNR随能量变化曲线,进而得出能谱CT成像中最佳能量点的单能图像;B组门静脉期采用能谱扫描模式扫描,双电压快速切换,从扫描数据中重组出60keV的单能量图像,并加上40%的ASiR。C组门静脉期采用常规肝脏增强扫描模式扫描得到门静脉期扫描图像。采用单因素方差分析比较3组图像中门静脉、肝实质的平均CT值及其差值、图像噪声及CNR。由2名放射科医师在盲法下对3组图像进行主观图像质量评分。结果:门静脉最佳CNR单能量水平集中在55.87keV左右。在A、B、C组图像的CNR分别为6.81±1.87、8.09±2.29、3.30±1.08,图像质量评分分别为4.28±0.58分、4.35±0.56分和3.58±0.46分。A、B组的CNR和图像质量评分均显著高于C组(P0.001)。结论:MSCT门静脉成像中最佳CNR单能量与60keV+40%ASiR图像较常规螺旋CT图像成像质量大大提高,均可在临床血管成像方面广泛推广。
[Abstract]:Aim: to investigate and evaluate the quality of portal vein images reconstructed by gemstone energy spectrum CT single-energy imaging and adaptive statistical iterative reconstruction, and to compare them with those of traditional multi-slice spiral CT. Methods: 90 patients with malignant tumor were randomly divided into group A (the best CNR single energy group) according to the digital table method. Group B (60keV 40%ASiR group) and group C (routine spiral CT group) had 30 cases in each group. The portal vein phase of group A was scanned with energy spectrum scanning mode and the double voltage was switched rapidly. The single energy images of the 40~140keV energy segment were reconstructed from the scanning data, and the curves of the main portal vein CNR with energy were obtained, and then the single energy images of the best energy points in the energy spectrum CT imaging were obtained. In group B, the portal vein phase was scanned by energy spectrum scanning mode, and the dual voltage was switched rapidly. The single energy image of 60keV was reconstructed from the scanning data. Combined with 40% of ASiR.C group, the portal phase images were obtained by conventional liver enhanced scanning mode. Single factor ANOVA was used to compare the mean CT value and its difference of portal vein and liver parenchyma, image noise and CNR. in three groups. The subjective image quality of three groups was evaluated by two radiologists under blind method. Results: the best single energy level of portal vein CNR was around 55.87keV. In A, B, C groups, the CNR was 6.81 卤1.87, 8.09 卤2.29, 3.30 卤1.08, the image quality scores were 4.28 卤0.58, 4.35 卤0.56 and 3.58 卤0.46 respectively, A, B and C were 6.81 卤1.87, 8.09 卤2.29, 3.30 卤1.08, respectively. The scores of CNR and image quality in group B were significantly higher than those in group C (P 0.001). Conclusion: the best imaging quality of CNR single energy and 60keV 40%ASiR images in MSCT portal vein imaging is much better than that of conventional spiral CT images, and both of them can be widely used in clinical angiography.
【作者单位】：北京协和医学院中国医学科学院肿瘤医院影像诊断科;
【分类号】：R816.5

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