Computerized Tomography (CT) is the new gold standard in veterinary surgery for imaging bones, joints and the spine (figure 1). A CT scanner emits a series of narrow beams as it moves through an arc, unlike an X-ray machine, which sends just one radiation beam. Tomography is the process of generating a 2-dimensional image of a slice or section through a 3-dimensional object. A good analogy is like looking at one slice of bread within the whole loaf. These images can then be reconstructed to clearly show the area of concern. An example is a view of a dog with an intervertebral disc herniation (figure 2).
The CT scanner uses digital geometry processing to generate a 3-dimensional (3-D) image. The 3-D image is produced after many 2-dimensional (2-D) X-ray images are taken around a single axis of rotation - in other words, many pictures of the same area are taken from many angles and then placed together to produce a 3-D image (figure 3).
At Colorado Canine Orthopedics and Rehab, CT scanning is routinely used for all spinal disorders, especially intervertebral disc herniation, elbow dysplasia, tarsal and carpal problems and complex fractures. The accuracy and speed of CT scans have been improved with the application of spiral CT. Most scans at CCOR can be performed with sedation alone.