Abdominal CT angiography in infants and young children after liver transplantation:Comparison on image quality and radiation dose between spectrum CT and low tube voltage scanning
Objective To compare image quality and radiation dose for abdominal CT angiography(CTA)in infants and young children after liver transplantation using energy spectrum CT and low tube voltage scanning.Methods Totally 41 infants or young children after liver transplantation were included,including 22 cases who underwent energy spectrum CT(energy spectrum group)and 19 cases who underwent low tube voltage(80 kV)CT scanning(low tube voltage group).50 keV single energy images of energy spectrum group were extracted to observe abdominal blood vessels.Subjective and objective evaluation on image quality were performed,the latter aimed at CT value and noise value of hepatic artery and portal vein,the contrast and contrast-to-noise ratio(CNR)of hepatic artery and portal vein.The examined volume CT dose index(CTDIvol),dose-length product(DLP)and effective dose(ED)of both groups were recorded.Results No significant difference of subjective image quality score was found between groups(P>0.05).In low tube voltage group,during arterial phase,CT values of hepatic artery,contrastarteries and CNRarteries were higher,and during the portal vein phase,CT values of hepatic artery,liver tissue noise,contrastportalvein and CNRportalvein were all higher than those in energy spectrum group(all P<0.05).CTDIvol,DLP and ED in energy spectrum group were higher than those in low tube voltage group(all P<0.05).Conclusion Compared with energy spectrum CT,low tube voltage CT scanning combined with iterative reconstruction technology could result better image quality and lower radiation dose for abdominal CTA in infants and young children after liver transplantation.