RESUMO
【Objective】 To compare the enhancement effects of lean body weight （LBW） and total body weight （TBW） as indexes to calculate the contrast agent dosage under the condition of energy spectrum CT scanning. 【Methods】 A total of 218 patients who received liver enhancement CT from November 2018 to January 2019 were enrolled in this study. There were 101 patients in LBW group and 117 patients in TBW group. Both groups were scanned by energy spectrum CT， and the parameters of scanning and reconstruction were identical. The contrast agent dose was 500 mgI/kg （LBW） in LBW group and 450 mgI/kg （TBW） in TBW group， and the injection rate was 2.8 mL/s. Images were transferred to a GE AW4.7 workstation and the 50 keV monochromatic images were analyzed. We compared the dosage of contrast medium， CT value of aorta in arterial phase （HU-aorta）， hepatic enhancement CT value in venous phase （-liver）， the rate of reaching the enhancement standard and variability in the two groups. 【Results】 Compared with TBW group， LBW group had lower contrast agent dosage， HU-aorta and ∆-liver （P0.05）. The variation rate of HU-aorta and ∆-liver in LBW group was lower than that in TBW group. Using LBW as an index to calculate the dosage of liver enhanced CT also made the enhancement of liver parenchyma more consistent in different patients. 【Conclusion】 Even on the premise of energy spectrum CT scanning， using LBW-based contrast injection in liver enhanced CT can not only reduce contrast dose， but also make the enhancement in liver parenchyma more consistent among different patients.