Objective:To improve the computed tomography portal venography by using the combination of virtual monoenergetic image and iterative reconstruction.Methods:Thirty patients were included in this prospective study.Dual energetic computed tomography portal venography was performed with iterative reconstruction(1,3,5 level),and then the virtual monoenergectic images(40KeV、60KeV、80KeV、100KeV、120KeV、140keV)and classic polychromatic images(120KeV)were reconstructed by using three groups of iterative data.Finally,twenty-one group of images were acquired from each patient.Average CT value,noise,single-noise ratio(SNR),contrast-noise ratio(CNR)were measured by two radiologists independently,and the subjective scoring was also performed for each group of image.Intraclass correlation coefficient(ICC)was used for consistency evaluation between two group of independent data,and ANOVA was used to compare the indicators.Results:The consistency of measurement between two radiologists was excellent in CT value,CNR,noise and subjective scoring of portal vein with ICC value of 0.95,0.93,0.87,0.80.The objective indicator of image quality had significantly statistical difference among various iterative level and mononenergetic combinations(P＞0.001).The CT value of portal vein based on 40 KeV monoenergetic image was significantly higher than other monoenergetic(P＜0.001).The CNR of 40Kev was also significantly higher than other monoenergetic image in the same iterative level(P＜0.001),and the subjective scoring had significantly increased(P＜0.05)with the highest score in A3-40KeV monoenergetic image.Conclusion:The combination of ADMIRE 3 iterative reconstruction and 40Kev virtual monoenergetic image was valuable to increase the CNR of portal vein and lower the image noise compared to classic 120 KeV polychromatic image,and was helpful for precision imaging of portal vein.
维普
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