What is a CT scanner?
CT stands for computed tomography and it is an advanced imaging technique that allows us to produce very detailed images of the internal structures of the body.
How does it work?
The scanner uses x-rays directed from multiple angles to produce cross-sectional images of the body. This means that we can look at small areas inside an organ or bone without the rest of the body structures getting in the way. Traditional x-ray images are a 2D presentation of a 3D structure and so there is lots of superimposition of the image, but this is not a problem with CT scans. Instead of one image, we get thousands of different images which we can scroll through to assess all areas of the body in fine detail.
When would we use it?
The applications of CT scanners in medicine and surgery are many and varied. It can be used to produce images of any part of the body. In particular it produces fantastic detail when looking at bone and cartilage, so is often used to study developmental problems of the elbows or shoulders. Many of these problems are not visible on traditional radiographs (x-ray films) but are obvious on CT images. We can detect small cracks and fragments in cartilage of as small as 1-2mm, allowing us to diagnose even the most subtle of lamenesses. CT also gives fantastic detail of the spine and we use it to diagnose disc problems or nerve compression that cannot be seen on radiographs. Internal chest or abdomen problems can be investigated quickly and in great detail.
What does a CT scan involve?
Humans can have conscious CT scans, but unfortunately animals will not stay still enough to allow this, so they have to be anaesthetised. The scan itself usually only takes 5 to 10 minutes and they are closely monitored by a vet and nurse as they would be during any other anaesthetic, making it very safe. Sometimes other procedures such as surgery or further imaging will be performed under the same anaesthetic. An injectable contrast agent is sometimes given to help show up areas of inflammation or tumours on the scans. CT scans are usually performed as a day procedure so that your pet should go home later that same day.
Although we still mostly use the 2D images produced by the CT scanner to make diagnoses, it can also produce detailed 3D images of bones and joints. This opens up lots of exciting avenues for surgery using 3D models and equipment that is produced by 3D printers on the basis of the animal’s individual scan. For example, drill guides can be made that fit precisely to your dog’s elbow joint, meaning that the screws or plates can be placed in exactly the right place, so reducing the chances of human error and hopefully providing a better outcome. These kind of technologies are developing all the time and South Moor Vets are proud to be the first practice to bring this service to the South Devon and Plymouth area.