摘要:
目的：比较不同水平的自适应迭代重建算法（ASiR）在腹部静脉血管最佳单能量成像中的图像质量，优化腹部静脉血管的成像参数。方法：回顾性分析上腹部能谱增强扫描检查患者30例。通过后处理工作站测量出最佳单能量值，分别用30% ASiR、40% ASiR及50% ASiR算法进行重建，分析比较三组图像及混合能量组图像中各静脉的CT值、图像噪声SDn、CNR及SNR。由放射科两名资深诊断医师采用双盲法对四组数据进行主观评估并记录评分。结果：混合能量组与其他三组在CT值、SDn、CNR及SNR均具有统计学差异（P<0.01）。30% ASiR组、40% ASiR组及50% ASiR组图像在CT值方面均无统计学差异（P>0.05）。在门静脉主干、肠系膜上静脉及脾静脉30% ASiR组与50% ASiR组之间的SDn、CNR、SNR均有统计学差异（P<0.05），30% ASiR组与40% ASiR组，40% ASiR组与50% ASiR组之间的SDn、CNR、SNR均无统计学差异（P>0.05）；在下腔静脉主干、左肾静脉、右肾静脉、肝左静脉、肝中静脉和肝右静脉30% ASiR组与50% ASiR组之间的SDn、CNR均有统计学差异（P<0.05），30% ASiR组与40% ASiR组，40% ASiR组与50% ASiR组之间的SDn、CNR均无统计学差异（P>0.05），三组图像之间的SNR均有统计学差异（P<0.05）。结论：最佳单能量（65keV）+40% ASiR在腹部静脉血管的成像质量较其他三组有所提高，可以在临床腹部静脉血管成像方面广泛应用。
Abstract:
Objective: To compare the imaging quality of different levels of the adaptive algorithm of iterative reconstruction (ASiR) in abdominal venous optimal single energy image to optimize imaging parameters of abdominal vein. Materials and Methods: Retrospective analysis was performed on 30 patients who underwent CT upper abdomen enhancement scan. All the subjects were scaned with spectral model and optimal single energy images were calculated using postprocessing workstation, and then reconstructed with ASiR 30%, ASiR 40% and ASiR 50% algorithm respectively. Finally, three group images of different ASiR levels were acquired. The CT value, image noise, contrast noise ratio (CNR) and signal noise ratio (SNR) of all abdominal vein were compared among the images of the three single energy groups and one mixed energy group by using single factor analysis of variance (ANOVA). The data of four groups were subjectively evaluated by two professional diagnostic physicians using double blind method. Results: The original spectral CT data were processed to acquire the 65 keV images, which were reconstructed with 30% ASiR, 40% ASiR and 50% ASiR, respectively. Together with the mixed energy group, finally four groups were obtained. There were statictically significant differences of CT value, image noise, CNR and SNR between the mixed energy group and the other three single energy groups (P<0.01). There was no significant difference in CT value among 30% ASiR group, 40% ASiR group and 50% ASiR group (P>0.05). For the portal vein trunk, mesenteric vein and splenic vein, there were significant differences of image noise, CNR and SNR between the 30% ASiR group and the 50% ASiR group (P<0.05), while no differences of that parameters between the 30% ASiR group and the 40% ASiR group, as well as 40% ASiR group and the 50% ASiR group (P>0.05); For the inferior vena cava trunk, the left renal vein, the right renal vein, the left hepatic vein, the middle hepatic vein and the right hepatic vein, there were significant differences of image noise and CNR between the 30% ASiR group and the 50% ASiR group (P<0.05), while no differences of that parameters between the 30% ASiR group and the 40% ASiR group, as well as 40% ASiR group and the 50% ASiR group (P>0.05); There were significant differences of SNR among the three groups (P<0.05). Conclusion: For the abdominal veins, the imaging quality of the optimal single energy (65keV) +40% ASiR is better than that of the 65keV+30% ASiR, 65keV+50% ASiR and the mixed energy group, which can be widely used in clinical abdominal venous angiography.
百度学术
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