Advanced Imaging of the Spine in Small Animals

Computed tomography (CT) and magnetic resonance imaging (MRI) are now routinely used in the diagnostic investigation of spinal diseases. This review discusses the fundamentals of CT and MRI, the technical aspects of both modalities, and the CT and MR imaging features of the most common spinal diseases. Both CT and MRI offer significant advantages over survey radiographs and myelography. Whereas very few veterinary studies have been published demonstrating the benefits of CT or MRI over regular myelography, a wealth of data exists from studies on humans. 1 The few comparative veterinary studies confirm the findings seen in humans. The overall diagnostic sensitivity of MRI is superior to CT, and as such MRI can be used to image the vast majority of spinal disorders, with few exceptions (eg, spinal trauma caused by gun shot). Routine survey radiographs are always recommended before proceeding with advanced imaging because the area of interest may be more specifically localized, thus reducing scanning time, and severe spinal/ osseous lesions, such as hemivertebrae or discospondylitis, may be identified without the need of advanced imaging studies. However, depending on the clinical status and treatment plan, advanced imaging may still be needed.