Comparative rheology of low‐ and iso‐osmolarity contrast agents at different temperatures

Abstract

AbstractBackground: Several contrast media (CM) are used for diagnostic angiography and coronary percutaneous interventions. Catheter miniaturization allows performance of most diagnostic studies using 4–5 F catheters and interventions using 5–6 F catheters. As a result of catheter lumen downsizing and viscosity of CM, the operators are sometimes required to forcefully inject to produce adequate images. Methods and Results: The aim of the study is to perform a comparative rheology analysis between three different commonly used CM: iso‐osmolar, nonionic iodixanol, Visipaque®, (GE Healthcare); low‐osmolar, nonionic ioversol, Optiray®; and low‐osmolar, ionic ioxaglate, Hexabrix®, (Tyco Healthcare, US). The viscosity was experimentally assessed for temperature varying from 14 to 40°C. To reproduce clinical use, an experimental set‐up was used and the pressure developed to inject CM was evaluated at different temperatures and compared between the three CM. All three agents demonstrated a nonlinear inverse relationship between temperature and viscosity. At 14°C iodixanol showed a twofold increase in viscosity compared with ioversol and ioxaglate. At 40°C, the difference was reduced to 27%. At room temperature (20°C), the difference in pressure needed to inject CM was 10% between iodixanol and ioxaglate and 6% between iodixanol and ioversol. As the temperatures increased, the differences in pressure became less important, becoming negligible (1%) at 37°C. Conclusion: The viscosity of the iso‐osmolar nonionic contrast agent iodixanol showed a stronger dependence on temperature compared with ioversol and ioxaglate. The impact of differences in viscosity and pressure to inject between CM were minimized at 37°C. This emphasizes the importance of temperature control when using current low‐osmolar CM and iso‐osmolar CM with smaller sized catheters. © 2008 Wiley‐Liss, Inc.