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| A preliminary study of improving imaging quality on hepatic venography with low voltage andlow concentration of contrast media by energy CT |
XIE De-shun, LIU Ai-lian, CHEN Li-hua, LIU Jing-hong, ZHANG Long-min,
TONG Zi-bin, LI Ye, LV Ting-ting, CHEN An-liang, LIU Yi-jun, PU Ren-wang |
| Department of Radiology, the Frist Affiliated Hospital of Dalian Medical University, Dalian Liaoning 116011, China |
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Abstract Objective: To investigate the feasibility of energy CT with low concentration of contrast media and low voltage for improving imaging quality of hepatic vein on hepatic venography. Materials and Methods: 119 patients with body mass index(BMI) lower than 22 kg/m2 who were suspicious of abdominal diseases were recruited in this prospective study and underwent tripple-phase enhanced CT scan of adbomen from March to December 2013 in our hospital. According to the scan time, the patients were randomly divided into two groups: group A(September to December 2013) with high concentration of contrast medium(350 mgI/mL) and routine tube voltage(120 kVp), including 41 cases(male 26 cases, female 15 cases, aged 59.20±11.69, group B(March to August 2013) with low concentration of contrast medium(270 mgI/mL) and low voltage(80 kVp), including 78 cases(male 55 cases, female 23 cases, aged 61.96±11.90). At portal phase, 1.25 mm-slice conventional images and optimal monochromatic images were obtained, and reconstruction was conducted by volume rendering(VR) and maximum intensity projection(MIP). The image quality of hepatic venography and the intrahepatic branches by MIP and VR was evaluated in a double-blind manner on a five-point scale by two radiologists with 8 years and 6 years of experience in abdominal diagnostic radiology. Two independent sample T-test was used to compare the CT value of hepatic veins and the liver parenchyma, the image noise, the vein-to-liver contrast-to-noise ratio(CNR) and the figure of merit(FOM) in the two groups. Inter-observer agreement was assessed by Kapppa value in image quality scoring. This study was approved by the institutional review board of our hospital. Results: The Kappa value of the image quality of left, middle and right hepatic veins by portal venography was good in group A(0.808, 0.852, 0.851, respectively) and group B(0.923, 0.937, 0.899, respectively). The CT values of the hepatic veins and liver parenchyma, image noise, CNR, FOM in group A were significantly lower than those in group B. Conclusion: Monochromatic images of energy CT with low concentration of contrast media and low voltage are feasibile for improving imaging quality of hepatic veins.
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Received: 16 June 2014
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Corresponding Authors:
LIU Ai-lian
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2014, Vol. 25 
