Kai Zhao MD, Presenter: Nothing to Disclose

Jia Liu, Abstract Co-Author: Nothing to Disclose

Yu Dong Zhang PhD, Abstract Co-Author: Nothing to Disclose

Xiaoying Wang MD, Abstract Co-Author: Nothing to Disclose

To compare the effect of different iodinated contrast medium on renal filtration function by multi-phase dual-energy CT.

A total of 11 New Zealand White Rabbits (2.5 kg-3.0 kg) were in this study. Experiments were conducted on a fast kVp-switching dual-energy CT scanner  with dual energy scan mode. On the first (baseline) day, all the rabbits were injected with 4ml iopamidol (370mgI/mL). Then serial three-phase dual-energy CT scans of rabbits’ kidneys were performed at 20, 40 and 60 minutes after iodine administration. On the second day, rabbits were divided into 2 groups randomly: 1) iopamidol group, 6 rabbits received large dose (5.0 ml/kg) monomeric, low-osmolality iopamidol (370mgI/ml); 2) iodixanol group, 5 rabbits received large dose (5.8 ml/kg) dimeric, iso-osmolality iodixanol (320mgI/ml). The total iodine administered was equal between the 2 groups. CT were performed at 20, 40 and 60 minutes after injection. On the third day, first day’s procedures were done again to all the rabbits. On AW 4.6 workstation, the iodine-based maps were generated. The average iodine concentration of 6 ROIs in the cortex of left kidney was used to quantify the iodine content at that time point. By adopted a one-compartment model and pharmacokinetical model C(t) = Cmaxe−Qt , with 3 iodine concentrations at the 3 time points, a similar straight line after natural logarithm conversion could be fitted. And the slope represented eGFR.

In iopamidol group, eGFR of the three days were 7.71±4.11, 2.49±0.86 and 3.82±1.47 (×10-3 min-1) (p=0.007). In iodixanol group, eGFRs were 8.75±5.12, 9.14±5.75 and 3.67±5.69 (×10-3 min-1) (p=0.081). Between the two groups, there was no significant difference before administration (p>0.05), but significant difference appeared after high dose of contrast medium administration (p=0.020). The obvious difference disappeared on the third day (p>0.05).

Iodinated contrast medium causes obvious deterioration on renal filtration function, which is still below the normal level until 24 hours after contrast administration. Iopamidol cause more deterioration on renal filtration function, which appears quickly after administration.

Our result shows that different iodinated contrasts have different influence on kidney, which may be helpful to understand the pathogenesis of contrast induced nephropathy (CIN). It can guide us to choose appropriate contrast medium.

Zhao, K, Liu, J, Zhang, Y, Wang, X, Comparison of eGFR Changes after Injection of Different Iodinated Contrast Medium by Multi-phase Dual-energy CT: A Time Course Study in Rabbit Model.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14003619.html