To compare the CT imaging performance of a novel intravenous carboxybetaine zwitterionic–coated tantalum oxide (TaCZ) nanoparticle CT contrast agent with that of a conventional iodinated (Iopamidol) contrast agent in a rabbit model
Material und Methoden
Four rabbits were serially placed inside an adipose-equivalent encasement emulating normal abdominal girth of 102 cm and scanned on a Spectral CT scanner (Philips IQon, Best, Netherlands) at arterial and venous delays after intravenous injection of 540 mg element (Ta or I) per kilogram of body weight of TaCZ or Iopamidol. For each time point, contrast enhancement of the aorta, portal- and hepatic veins, as well as the liver parenchyma were measured in Hounsfield Units (HU) by placing circular regions of interest. Effective Z-numbers were also measured for the aorta and liver parenchyma. Findings were compared using a paired T-test for independent samples.
Mean peak enhancement for both arterial and venous phases were higher for TaCZ than for Iopamidol in the aorta (365 vs. 264 HU p=0,62; and 227 vs. 142 HU p<0,001), portal vein (406 vs. 220 HU p=0,01; and 251 vs. 145 HU p=0,001), hepatic vein (227 vs. 168 HU p=0,34; and 257 vs. 145 HU p<0,001) and liver parenchyma (166 vs. 112 HU p=0,049; and 147 vs. 110 HU p=0,029). Effective-Z measurements were significantly lower in both the aorta (6,72 vs. 9,94 p=0,019; and 7,04 vs. 8,79 p<0,001) and liver parenchyma (7,01 vs. 8,24 p=0,002; and 7,07 vs. 8,14 p<0,001) after injection of TaCZ compared to Iopamidol.
An experimental tantalum nanoparticle–based intravenous contrast agent showed greater contrast enhancement compared with Iopamidol at arterial and venous delay phases in a rabbit model; spectral decomposition algorithms allow differentiation of tantalum and iodine which indicates valuable applications for multi-energy CT imaging.