Background: Evaluation of cardiovascular function in mice using micro-CT requires that a contrast agent (CA) be
administered to differentiate the blood from the myocardium. eXIA 160, an aqueous colloidal poly-disperse CA with a
high concentration of iodine (160mg I/mL), creates strong contrast between blood and tissue with a low injection
volume. In this study, the blood-pool enhancement time-course of eXIA 160 is monitored over a 24-hour period to
determine its optimal use during cardiac function studies.
Methods/Results: 8-second scans were performed (80kVp, 110mA) using the GE Locus Ultra micro-CT scanner. Male
mice (black, 22-24g) were injected via tail vein with 5 μL/g body weight eXIA 160 (Binitio Biomedical Inc.). A
precontrast scan was performed; following injection, mice were scanned at 15, 30, 45, and 60 minutes, 2, 4, 8, 24, and 48
hours. Overall, the highest contrast in the left ventricle occurred at 5 minutes (687 HU). Uptake of the CA by the
myocardium was also observed: myocardial tissue showed increasing enhancement over a 4-hour period, remaining even
once the contrast was eliminated from the vasculature.
Conclusion: eXIA 160 provided high contrast between blood and myocardial tissue for a period of 30 minutes following
injection. Notably, this CA was also taken up by the myocardium and provided continued enhancement when the
contrast agent was eliminated from the blood, making LV wall function studies possible. In conclusion, eXIA 160, with
its high iodine concentration and targeted tissue uptake characteristics, make it an ideal agent to use when evaluating
cardiovascular function in mice.