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PET Scans vs. CT Scans for Pets: What's the difference?

You'll likely hear many medical terms and acronyms if your pet needs diagnostic imaging. In this post, we'll compare and contrast a CT scan and a PET scan and share how they help a veterinarian diagnose your cat or dog's health condition.

Veterinary Diagnostic Imaging

Diagnostic imaging plays an integral role in helping veterinarians diagnose many illnesses and conditions in pets. Since our cats and dogs can't speak for themselves to tell us what's wrong, it's even more important that the people treating your pet have access to diagnostic technology such as CT and PET scanners to accurately identify health issues so they can be quickly and effectively treated. 

What is the difference between a CT scan and a PET scan?

While a CT scan captures a still, in-depth image of your pet's bones, organs, and tissues, a PET scan allows us to see how the body's tissues operate on a cellular level. 

  • Different materials are used in CT and PET scanners. CT scans pass X-rays through the body to create images. During a PET scan, radioactive material emits energy that a special camera can detect. 
  • A PET scan can take anywhere from 45 minutes to several hours to complete. A CT scan can be completed in minutes, which makes it a great option for emergency circumstances in which a veterinarian needs to act quickly. 
  • While a small amount of radiation may remain in your pet's body for a short period of time after a PET scan, no radiation will stay in an animal's body after a CT scan. 
  • Molecular activity during a PET scan can help a veterinarian detect the very earliest signs of disease. This is why a PET scan is a highly reliable tool for detecting cancer. With a CT scan, signs of a problem can be seen after the disease has started to change the structure of the tissues or organs. 

How CT Machines Work 

"CT" is an acronym for computed tomographic imaging. Also called a "cat scan", this diagnostic technology produces multiple individual images or "slices" throughout a specific area of the body through the use of radiation (X-rays) and a computer. Think of individual slices of bread that make up a complete loaf and you'll have an idea of the type of image produced by a CT scanner. 

The CT machine produces two-dimensional slices of a section of your pet's anatomy, then reconfigures them into a complete image to view. These slices can also be used to create three-dimensional reconstructions, which can be very useful for surgical planning and other purposes. The images are produced, then sent to a veterinary specialist to review and interpret. 

What PET Scans & CT Scans Are Used For

CT Scans

The high-resolution images captured by the CT machine assist veterinary professionals in evaluating the anatomy of your cat or dog in great detail - details that can't typically be seen with standard X-rays.

CT scanners offer excellent details of bony and soft tissue structures in the body. The most common areas of the body veterinary professionals X-ray with CT technology include the nasal cavity, spine, chest/lungs, inner ear, and joints/bones. Veterinary professionals could also use CT machines to evaluate the thyroid gland, lymph nodes, vascular structures, the skull/brain, and abdominal organs.

PET Scans

A CT scan can also be combined with a contrast agent that is given to your pet intravenously (IV), this allows vets to see increased areas of blood flow in the body. This helps detect a variety of cancer and areas of inflammation. In people Positron Emission Tomography (PET) scans are designed to give doctors an in-depth look at the way a patient's organs and tissues are functioning. Most of the time PET scans are used to find and monitor various cancers.

What You Can Expect From Your Pet's PET/CT Scan?

For the CT machine to capture high-quality images, it's imperative for the patient being imaged to stay as still as possible when the scan is being taken. When it comes to people, it's usually enough just to tell them to hold their breath and not to move. Although, this technique can't be used for cats and dogs, making general anesthesia or heavy sedation essential.

The vital signs of your animal companion are monitored closely when they are under anesthesia during the entire CT. CT scanners are generally highly efficient, and a typical CT scan usually doesn't take very long. After the CT, the vet will evaluate the images taken of your pet, develop a detailed report with findings, and make the necessary diagnostic recommendations.

Do you have more questions about diagnostic imaging for pets? Contact our Englewood veterinarians today. We would be happy to answer questions and address any specific concerns. 

New Patients Welcome

VRCC Veterinary Specialty & Emergency Hospital in Englewood is always accepting new patients! Our board-certified specialists and emergency veterinarians are passionate about restoring good health to Denver Metro area pets.

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