Transverse CT, myelogram, cervical vertebral column, horse

Transverse CT image at the level of the C6-C7 articular process joints in a horse, displayed in a bone window, after positive contrast has been injected in the subarachnoid space (eg, myelogram). The left of the patient is to the right of the image. There is focal marked attenuation of the right lateral aspect of the contrast column (arrow) secondary to articular process osteophytosis/enlargement and presumptive articular process joint capsule distention. This area of compression is not detectable on sagittal reconstructed images and would not be visible on a radiographic myelogram, given the lateral location.