Impact of different iodine concentrations on abdominal enhancement in biphasic multislice helical CT (MS-CT)

Impact of different iodine concentrations on abdominal enhancement in biphasic multislice helical CT (MS-CT). To evaluate if different iodine concentrations of a contrast material (c.m.) have an impact on abdominal enhancement in MS-CT during the arterial (AP) and portal venous phase (PVP). 75 patients underwent biphasic CT of the abdomen. They were assigned to three equally sized groups. For all patients a non-ionic c.m. (iopromide, Ultravist, Schering AG, Berlin) with different iodine concentrations and a constant total iodine load of 37 g with an injection flow rate of 4 ml/s was used. The volume of the c.m. differed depending on the iodine concentrations: group 1 (123 ml of 300 mgl/ml); group 2 (112 ml of 335 mgl/ml); group 3 (100 ml of 370 mgl/ml). The scan delay was optimized by using a bolus tracking device. The groups were compared concerning their mean enhancement of aorta, spleen, pancreas, and liver in the AP and PVP. The comparison of the three groups showed an improved enhancement in aorta, spleen, and pancreas during the AP by using the higher c.m. concentrations. In the PVP the c.m. enhancement of aorta, liver, spleen, and pancreas was independent of the administered c.m. concentration. Higher iodine concentrations of c.m. have a positive impact on abdominal enhancement during the AP. The concentration has no influence on the enhancement during the PVP of abdominal MS-CT.