advances in diagnostics: dr. kim smyth explains CT scans
Veterinary medicine of today is not your grandfather’s veterinary medicine. We’ve come a long way over the years, for sure. If you’ve ever read any of James Herriot’s books, you know exactly what I mean! Things that were considered state-of-the-art even a decade ago are now commonplace, even in your regular veterinarian’s office. If your pet needs an x-ray or blood work, he’s lucky enough to be able to get that right down the street!
There are some diagnostics, however, that you’ll need to travel for, and CT scans are one of those things.
What is a CT scan?
Computed axial tomography, also known as CAT scans or CT scans, use the same x-ray beams that are used for plain old x-rays at your general practitioner’s place, but CT scans use them in a different way. One of the downfalls of regular x-rays (or radiographs, as we like to call them), is that the image that is formed is two dimensional, while the object that was x-rayed is three dimensional. Radiographs result in overlapped organs, which can create a pretty complicated picture.
CT scans, on the other hand, use a very narrow x-ray beam that rotates around your pet, creating thin slices of the body part in question. Imagine an olive loaf. (Gross, I know, but you don’t have to eat it. You just have to picture it.) If the loaf itself were transparent, and you just put it on the table and looked through it, you’d see olives willy nilly. If you wanted to count the olives, you’d be hard pressed to do so because some olives would surely be obscuring other olives underneath them. Now, imagine slicing the olive loaf into many thin pieces and viewing each slice of loaf individually. Looking at one slice of olive loaf, it is easy to count the number of olives! The same is true for CT scan images—there is a place for each organ and each organ has its place!
These days, CT scans can even help veterinary teams like those at the University of Pennsylvania create a 3D print of a pet's skull so that surgeons can examine an actual replica prior to surgery, allowing them to more accurately plan surgical approaches, custom-tailor implants and reduce anesthesia time, allowing for a better surgical result. A Petplan policyholder in California recently took advantage of this new technique to get a 3-dimensional print of her Mastiff's skull to help the doctors plan for surgery.
Where are CT scans useful?
CT scans are especially useful in specific areas of the body. MRI is still preferred for brain and spinal cord injuries, but CT scan can be used in these areas as well. Other places where CT scans excel are:
- Nasal and sinus cavities
- Thoracic abnormalities, particularly in the lungs
- Abnormalities of the ureter
- Dental disease
- Orthopedic conditions and fracture repair planning
- Abdominal abnormalities
What to do if you need a CT scan
If your pet needs a CT scan and you’re not already at a referral center, you’ll probably need to go there to get this particular kind of diagnostic test. CT scanners are just more expensive than your general practitioner can afford. Prior to having a scan, your pet will be anesthetized to ensure that he or she is completely still for the scan. CT scans have an advantage over MRIs in that they are quick—where MRIs can take up to an hour, some CT scans can be finished in 10 minutes.
We are so lucky to have advanced imaging like CT scans and MRIs available for our pets. Hopefully, your pet will never need these tests, but you’ll be glad they're around if you do!