A Multi-center study on Individualized Contrast Media Protocols in Abdominal Computed Tomography： Dose calculation based on the Liver Volume

Abstract

Abstract Objectives: To evaluate the attenuation of a liver volume–adapted contrast protocol compared with the injection protocol based on body surface area in computed tomography of the abdomen. Materials and Methods:1604 patients referred for unenhanced and multiphase enhanced abdominal CT scanning in a portal venous phase were included inthe study. 748 patients in Group 1 received injected iodine dose with the equation of liver volume (mL) × 7.225 + 16486.754 (mg). 856 patients in Group 2 received a body surface area-adapted protocol with the equation: 17600 mg iodine per m2. Attenuation (HU) in 8 segments of the liver was observed. Subjective image quality was assessed by the Likert scale. Differences between groups were statistically analyzed (P < 0.05 was considered statistically significant). Results:No significant differences in baseline characteristics were found.The injected iodine differed significantly between groups (P < 0.001). The milligrams of iodine per kilogram in Group 1 was 445.59 ± 100.18 which was lower than previous studies of total body weight-adapted protocols with a better effect on higher weight population. Besides, a significant difference wasfoundinthe attenuation of the liver between the two groups.Group 1 showed better aggregation to the standard of 50 HU. Conclusions: Liver volume-adapted contrast media protocol resulted in more homogeneous enhancement of the liver parenchyma and its enhancement efficiency is closer to the theoretical standard, whereas injected iodine can be reduced in a large percentage of the population.