What Is Veterinary Diagnostic Imaging for Felines?

Veterinary diagnostic imaging includes radiographs (x-rays), ultrasound, MRIs and CT scans, all of which are used as diagnostic tools to collect information about your cat's health. The vast majority of imaging is non-invasive and completely painless. However, some imaging may require sedation or even anesthesia because the cat must be kept still to allow for adequate images to be produced. Veterinarians use these images to collect information on your cat when making a medical or surgical plan.

When Is Veterinary Diagnostic Imaging Necessary for Your Cat?

After your veterinarian has examined your cat, he or she may want to collect more information before making a diagnosis and a treatment plan. X-rays are usually the first line of imaging. If an x-ray is inadequate for diagnosing your cat, the next step may be to take an ultrasound of a particular area of the patient's body.

For instance, if your cat is vomiting and feeling ill, your veterinarian may take an x-ray to look for possible causes such as intestinal obstruction. Even if the x-ray reveals signs of obstruction, it may be prudent to follow up with an abdominal ultrasound before proceeding with surgery. An ultrasound will provide greater detail of the affected area and therefore allow for a higher degree of confidence in the treatment plan before moving forward with surgery. Sometimes x-rays and ultrasound lead to a definitive diagnosis, but at other times they are an important part of a larger puzzle the veterinarian must solve when creating a treatment plan for your cat.

Four types of Veterinary Diagnostic Imaging used to assist in diagnosing your cat's condition are:

  • X-ray
  • MRI
  • Ultrasound
  • CT scan

More information on each of these types of radiography is provided below.

Cat X-Rays

Cat x-rays have been used throughout the medical community for many decades. Cat x-rays are by far the most regularly used form of diagnostic imaging in the veterinary industry because they are cost-effective (comparatively speaking) and they can accurately diagnose the state of skeletal structure and composition, large body cavities, and the presence of foreign objects. Cat x-rays are painless, but some cats may benefit from sedation to reduce anxiety and stress.

Cat x-rays usually proceed as follows:

  • The cat is placed on the x-ray table.
  • A technician positions the x-ray machine so that the x-ray beam targets only the area of interest.
  • Modern x-ray equipment emits less radiation, so occasional use is perfectly safe for your cat.
  • Because cat x-rays are static images, the procedure usually requires less time than a procedure like an MRI.

Cat x-rays have traditionally been captured on actual film, and still can be when necessary. Typically, however, we take digital x-ray images that we store on a secure server accessible to our veterinarians at any time. We can also easily share digital files with specialists when the need arises.

Cat Ultrasound

A cat ultrasound is the second most common type of diagnostic imaging tool veterinarians use to diagnose a cat's medical condition. Ultrasounds use sound waves to examine and photograph internal tissues in real time. An ultrasound enables a veterinarian to view organs from angles not easily achieved with x-rays.

A cat ultrasound usually proceeds as follows:

  • A technician gently presses a small probe against the cat's body.
  • Sound waves emitted by the probe are directed to various parts of the cat's abdominal area by manually shifting the probe's position.
  • The sound beam changes velocity while passing through tissues of varying density, which creates echoes.
  • Our ultrasound machine converts those echoes into electrical impulses that are further transformed into a digital image that represents the appearance of the tissues.
  • These images can be viewed in real time by a veterinarian as well as stored for further review.

In modern scanning systems like those that GoodVets has on-site and uses on our feline patients, the sound beam sweeps through the body many times per second. This produces a dynamic, real-time image that changes as the cat ultrasound device moves across a cat's body. We can use the results of an ultrasound to determine what ails your cat and to devise the most effective treatment protocol.

Common symptoms that may lead a veterinary to use ultrasound include vomiting, weight loss, kidney impairment or blockage, and heart disease.


Magnetic resonance imaging, or MRI, is the newest form of diagnostic imaging being used for both human and veterinary medicine. Cat MRI equipment generates a powerful magnetic field used to produce detailed anatomic images of a cat's body. A cat MRI is regarded as entirely safe.

A cat MRI procedure usually proceeds as follows:

  • Cats must be sedated for this procedure because they cannot be restrained by humans and must remain still during the procedure.
  • The cat is placed in a tubular electromagnetic chamber.
  • The cat's body is continuously pulsed with radio waves for a period of time, usually 10-20 minutes.
  • Pulses cause the cat's body tissues to emit radiofrequency radiation that can be detected by the MRI equipment. Many repetitions of these pulses and subsequent emissions are required in order to generate adequate digital feedback for the equipment to interpret.
  • The feedback is then converted into images that can be displayed on a screen saved for future study.

A cat MRI is not used as regularly as an x-ray or ultrasound because the equipment is very expensive, very large, and requires specially trained technicians to operate. However, GoodVets offers comprehensive cat MRI services because we believe that facilitating complete feline care means having all the tools and training necessary to do so.

CT Scans for Cats

CT scans, also known as cat scans, are computer-enhanced x-ray procedures most often used to evaluate complex parts of the body such as the head, chest, some joints, and various internal organs. CT scans show different levels of tissue density and produce more detailed images than x-rays. Unlike MRI, CT scans for cats do not use magnetic field waves so they cannot compare changes in fluid levels due to inflammation or bleeding. Therefore, CT scans for cats are used in situations for which an MRI is deemed unnecessary but a traditional x-ray is inconclusive or insufficient.

CT scans for cats usually proceed as follows:

  • Cats must be sedated for this procedure because they cannot be restrained by humans and must remain still during the procedure.
  • The cat is placed on a motorized bed inside a CT scanner, a machine that takes a series of x-rays from various angles.
  • When one series, or scan, is completed, the bed moves forward and another scan is taken.
  • A computer uses these scans to create cross-sectional images of the body part under investigation, and then display the images on a monitor. (An x-ray dye may be injected intravenously to make it easier to see abnormalities.)
  • By sequentially scanning an entire body area, an organ or other structure can be imaged without penetrating the body or disrupting neighboring structures.

CT scans for cats are most often used by our veterinarians to detect structural changes deep within a cat's body, including:

  • Tumors
  • Deep abscesses
  • Foreign bodies
  • Fractures

As with MRI equipment, CT scan equipment is very expensive, large and requires trained technicians to operate. However, in our mission to offer your beloved feline companion the full complement of diagnostic benefits, we provide CT scans for cats at our veterinary hospitals.

How Feline Radiographs Influence Veterinary Recommendations

The goal of feline radiographs is to formulate a diagnosis without performing invasive tests or procedures. For example, an x-ray might show evidence of a tumor of the spine that possibly involves the surrounding muscle. The addition of an MRI would reveal the tumor and the extent to which it encroaches on the surrounding muscle tissue. This type of information is crucial when offering a prognosis and treatment plan.

Veterinary diagnostic imaging offers our veterinarians an array of tools useful for diagnosing and treating illness and injury.

Contact Us for Cat Radiographs Today

If you are concerned that your cat might be injured or experiencing internal problems, or if you'd like to discuss how feline radiographs can benefit your pet, please schedule an appointment with one of our veterinarians today.