Enhancement and safety of iomeprol-400 and iodixanol-320 in patients undergoing abdominal multidetector CT

The purpose of this study was to compare iomeprol-400 and iodixanol-320 for contrast enhancement and safety in patients undergoing liver multidetector CT (MDCT). 183 patients undergoing MDCT received equi-iodine (40 gI) iomeprol-400 (n = 91) or iodixanol-320 (n = 92) IV at 4 ml s(-1). Two off-site, independent, blinded readers determined the contrast density (in Hounsfield units (HUs)) in the abdominal aorta, inferior vena cava, portal vein and liver parenchyma during the arterial and portal phases. The mean contrast densities achieved were compared and 95% confidence intervals (CIs) estimated. Heart rate was measured at baseline and at post-dose peak, and a full safety assessment was performed. Study group demographics were comparable. Iomeprol-400 produced significantly greater enhancement of the aorta during the arterial phase (Reader 1: 337.3 HU vs 294.9 HU, 95% CI of difference (19.4, 65.5), p = 0.0004; Reader 2: 325.7 HU vs 295.3 HU, 95% CI of difference (6.6, 54.3), p = 0.01) and greater enhancement of the liver parenchyma during the portal venous phase (Reader 1: 115.1 H vs 108.6 HU, 95% CI of difference (0.27, 12.7), p = 0.04; Reader 2: 115.2 H vs 109.3 HU, 95% CI of difference (-0.1, 11.8), p = 0.05). Similar enhancement of the inferior vena cava and portal vein was noted. Comparably negligible increases in the mean heart rate were observed. Adverse events occurred in 1/91 (1.1%) subjects after iomeprol-400 and 4/92 (4.3%) subjects after iodixanol-320. In conclusion, iomeprol-400 produces greater arterial and portal phase enhancement and has a similarly negligible impact on heart rate and safety.