Image courtesy denverkid, Flickr
What is a CT scan?
A CT scan, also known as computed tomography scan, or CAT scan (Computed Assisted Tomography) is an advanced non-invasive medical imaging technique. The procedure uses a combination of x-ray imaging and a digital computer to produce detailed 3 dimensional images of the bones and tissues inside the body. In some patients, a contrast dye may be injected intravenously to make it easier to better define tumours or highlight certain tissues.
The CT machine looks like a large doughnut with a hole through the centre. During the procedure, the cat lies on a motorised table that is slowly passed through the hole. A giant ring (gantry) rotates around the body taking a series of x-rays taken at different angles to produce a cross sectional series of images. An x-ray produces a single images, while the CT scan produces hundreds. Think of an entire loaf of bread, which consists of a number of slices, once the images have been taken, the slices, which are 1 mm thick, are put together to evaluate the images as a whole.
Allows the veterinarian to look inside the body without invasive procedures such as endoscopy or exploratory surgery.
Produces considerably more advanced images compared to traditional x-ray or ultrasound.
Indications for CT in cats:
- Blood clots
- Internal injuries to the organs and blood vessels
- Vascular anomalies
- Diagnose and stage cancer and look for signs of pulmonary metastasis (spread of tumours to the lungs)
- Lung lobe torsion
- Heart disease
- Ear disease (polyps, middle ear infection, cancer)
- Foreign bodies
- Broken bones
- Bone infection
- Nasal disease (unexplained sneezing, bleeding, discharge, growths, aspergillosis)
- Internal bleeding
- Evaluate the organs for size, shape, abnormalities
- Detailed images of the joints for abnormalities and disease
- Disorders of the spine
Drawbacks and risks:
- Only available at veterinary referral centres or universities
- Expensive, especially for carers without pet insurance
- Low dose of radiation exposure
- Can not be used on pregnant cats due to the risks radiation exposure to unborn kittens
- Reaction to contrast material
- Anesthetic risks, especially in cats with heart conditions
How much does a CT scan cost?
The cost of a CT can vary but on average the procedure costs between $1000 – $2000 which will include a consultation, sedation or anesthesia, CT scan and a follow up radiology report.
The veterinarian will provide you with information on how to prepare the cat for a CT scan.
Due to the risk of regurgitation and aspiration, the cat will need to fast for several hours prior to the scan. Water can be left out until the morning of the procedure. These guidelines may vary from practice to practice and depending on the age and health status of the cat.
How long does a CT scan take?
The cat will be put under deep sedation or light general anesthesia as they must remain still. Staff will leave the room during the procedure, while the cat is monitored remotely using portable equipment.
This depends on the area to be assessed, but can be as fast as a few seconds to a few minutes.