Time Attenuation Curves for Equine Intravenous Contrast Enhanced Skull CT Using the Medial Saphenous and Cephalic Veins

Intravenous (IV) contrast administration during computed tomography (CT) of the equine head is routinely performed to delineate the extent of disease and differentiate between vascular and nonvascular tissue. Current equine scan protocols are extrapolated from human and canine studies. There have been no prospective equine studies describing the optimal time to image the patient after administration of contrast or the optimal site of contrast administration. Therefore, the current postcontrast times to scan and sites of contrast administration may not be appropriate for use in horses. The objective of this prospective crossover pilot study was to generate contrast enhancement curves for IV contrast injection via the medial saphenous vein and the cephalic vein. Both medial saphenous and cephalic venous contrast administration sites are effective for contrast-enhanced CT of the equine skull, with no pooling artifacts. Peak carotid artery enhancement occurred earlier than in the maxillary veins (109.12 s vs. 173.82 s).