What is Veterinary Feline Diagnostic Imaging?

Veterinary feline diagnostic imaging includes radiographs (x-rays), ultrasound, MRIs, and CT scans, all of which are used as diagnostic tools to collect information on 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 produce adequate images. Veterinarians use these images to collect information on your cat to help them make a medical and sometimes surgical plan.  Please note that at Seven Hills, we refer clients to a specialist for MRI and CT scans. 

When Is Veterinary Diagnostic Imaging Necessary?

After your veterinarian has examined your cat, he or she may begin collecting more information to lead to a diagnosis and a treatment plan. X-rays are usually the first-line imaging modality. The X-ray may lead to a diagnosis that allows them to move forward with a plan.  However, sometimes the next step may be an ultrasound to provide a more thorough or specific view of a particular area of the 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 or an obvious foreign body. The x-ray may show some signs of an intestinal obstruction; however, before proceeding to surgery, it would be prudent in some cases to follow with an abdominal ultrasound. The ultrasound will give more details of the area and, therefore, allow more confidence in the treatment plan to move forward with surgery. Occasionally, X-rays and ultrasound allow for a definitive diagnosis. Still, at other times, they provide additional information to help put the puzzle together and develop the best treatment plan for your cat.
The four types of Veterinary Diagnostic Imaging our veterinarians may utilize to assist in the diagnosis of your cat’s condition are:
  • X-Rays
  • Ultrasounds

Please note that we refer clients to a specialist for the following procedures:

  • MRI’s 
  • CT Scans
More information on each type of radiograph is provided below.
Cat X-Rays
Cat x-rays have been in use throughout the medical community for many decades. Cat X-rays are by far the most commonly used form of diagnostic imaging in the veterinary industry because they are cost-effective (comparatively) and can accurately assess skeletal structure and composition, large body cavities, and the presence of many foreign objects. Cat x-rays are totally painless, but some cats can 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 allows for low levels of radiation, and when used only occasionally, it is perfectly safe for your cat.
  • Because cat x-rays are static images, the procedure usually takes less time than an MRI.
Cat x-rays have traditionally been captured on film, and can still be when necessary. However, our X-ray images are now digital, allowing us to store them on a secure server that our veterinarians can access at any time and share with specialists, if necessary. 

Cat Ultrasounds

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 allows a veterinarian to see inside a cat’s body in real time, making it easy to view organs from angles not readily achievable with X-rays. The functioning of various organs can be observed to determine if they are malfunctioning.

A cat ultrasound procedure usually proceeds as follows:

  • A cat ultrasound technician gently presses a small probe against the cat’s body that emits digital sound waves
  • The sound waves 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 varying body tissue density, which causes echoes
  • Our ultrasound equipment converts these echoes into electrical impulses, which are then further processed into a digital image representing the appearance of the tissues.
  • These images can be viewed in real time by a veterinarian and stored for further review at any time.
In modern scanning systems like the ones Seven Hills Veterinary Hospital 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 is ailing your cat, and to devise the most effective treatment protocol. 
Common symptoms that may cause a veterinarian to use ultrasound include: vomiting, weight loss, kidney impairment or blockage, and heart disease. 

Cat MRI

Please note that at Seven Hills, we refer clients to a specialist for MRI services.
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 very powerful magnetic field, resulting in detailed anatomic images of whatever part of a cat’s body is being scanned. No X-rays are involved, and a cat MRI is considered extremely safe. 

A cat MRI procedure usually proceeds as follows:

  • Cats must be sedated for this procedure because humans cannot restrain them and must remain still during the procedure
  • For the procedure, a 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
  • The pulsing causes the cat’s tissues to emit radio-frequency waves that can be detected by the MRI equipment. Many repetitions of these pulses and subsequent emissions are required to generate sufficient digital feedback for the equipment to interpret.
  • The feedback is then converted into images that can be displayed on a screen and 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. Seven Hills Veterinary Hospital offers referrals to specialists for cat MRI services.

CT Scans for cats

Please note that at Seven Hills, we refer clients to a specialist for CT scans. 
CT scans for cats, also known as ‘cat scans’, are computer-enhanced cat 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 MRIs, CT scans for cats do not use magnetic fields, so they cannot detect changes in fluid levels caused by inflammation or bleeding. Therefore, CT scans for cats are used in situations where an MRI is considered 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 invasively penetrating the body or disrupting neighboring structures.
CT scans for cats are most often recommended by our veterinarians to detect structural changes deep within a cat’s body, including:
  • Tumors
  • Deep abscesses or foreign body presence
  • Fractures
Just like MRI equipment, CT scan equipment is costly, large, and requires trained technicians to operate. Seven Hills Veterinary Hospital offers referrals to specialists for cat MRI services.

How Feline Radiographs Influence Veterinary Recommendations

The goal of feline radiographs is to ascertain a diagnosis or obtain a final answer without having to perform further, more invasive tests or procedures. For example, an X-ray might show evidence of a tumor of the spine and possibly involve the surrounding muscle. An MRI would reveal the specific tumor and its extent within the surrounding muscle tissue. This type of information is very important for a prognosis and treatment plan.
Veterinary diagnostic imaging offers a range of handy tools in a veterinarian’s toolkit. Sometimes a diagnostic imaging session can prompt further diagnostics. This is why it is important to understand that diagnostic imaging may lead to a progressive fact-finding mission that must be undertaken to diagnose your cat’s ailment.
If you are concerned that your cat might be injured or experiencing internal problems, or to discuss how feline radiographs can benefit him or her, please contact us to schedule an appointment with one of our veterinarians today.