Intraarterial Injection of Iodinated Contrast Medium for Contrast-Enhanced Computed Tomography of the Equine Head.

The research looks into the use of iodinated contrast medium injections in arterial lines for contrast-enhanced computed tomography (CT) in horse heads. It investigates whether low-volume arterial contrast injections produce equivalent image quality to high-volume intravenous contrast administration, with the aim of minimizing the contrast amount used, reducing costs, and mitigating adverse reaction risks.

Research objective

• The main goal of this study was to test if low-volume intraarterial contrast medium administration can produce images of the same quality, and similar tissue attenuation as the standard practice of high-volume intravenous bolus administration. This could drastically cut costs and reduce the risk of any adverse medical reactions from using a large volume of contrast.

Methodology

• The study used a prospective cross-over experimental design with a sample of six horses. After anaesthetizing the horses, the researchers surgically exposed and catheterized the right carotid artery in each.
• Four CT scans were performed on the cranium of each horse: a baseline, immediately after intraarterial contrast injection, five minutes postinjection (returning to the baseline), and a final one following intravenous contrast administration.
• Prior to imaging, soft tissue attenuation in predetermined regions of interest (ROI) as well as length, width, and height of the pituitary gland were measured, and then repeated postmortem.

Findings

• All horses exhibited no adverse reactions to the contrast administration.
• In comparison to baseline values, both intraarterial and intravenous administration significantly improved soft tissue enhancement in some brain ROIs and the pituitary gland.
• The dimensions of the pituitary gland measured on postcontrast CT images mirrored those obtained postmortem, suggesting the accuracy of the imaging technique.

Conclusion

• The study concluded that low-volume intraarterial administration of contrast material in the horse head could yield adequately enhanced soft tissue images, similar to those produced by high-volume intravenous administration. Therefore, intraarterial administration could serve as a viable, cost-effective, and safer alternative to the current practice.